That's pretty much all the raid content WotLK offers currently. Sure there's 10 mans as well, but other than for achievements there's really no point doing those if you're already farming 25 man content.
So, how does one keep busy until 3.1 hits the live servers?
Make an alt
The most obvious thing to do, as well as probably one of the most useful ones. Having multiple characters allows you to readily have access to different crafting professions, or simply a main with crafting professions and an alt with gathering. With the release of WotLK the obvious first pick is Death Knights since they start at level 55.
Money should by no means be an issue. Daily quests give you plenty of cash, and simply cleaning up raids will pay you anywhere between 60-120g a night as well. If that doesn't warm up your pants then there's always the crazy farming spree for metals or herbs which can net you around 1000g in no more than a few hours or two. You'll spend more time putting stuff on the AH then actual farming... heh.
If you already have a Death Knight, then I can highly recommend making a Druid for their improved ability to farm herbs without shifting from flightform. Alternatively a hybrid of sorts due to the dual-spec feature coming up. Having a handy alt available is always useful, regardless of what some think.
As for myself, though I only got two level 80's, some of the 70's I raised during TBC have worked hard to get their professions up to the new levels. Getting all the glyphs and jewelcrafting patterns certainly is a p.i.t.a. that takes a lot of weeks to complete.
Farm achievement points
The ultimate of fake content to some, an extra accomplishment to others.
Obviously being sent around all of azeroth to '/love' some squirrels and other critters is plain and obvious fake content to keep us busy playing and paying for the game.
On the other hand, achievements like these can be challenging:
They test your DPS, coordination and ability to push your raid to it's limit. And in some cases luck with disconnects and poorly timed lag.... Still, most should be doable if you're farming all the current content. Also, The Twilight Zone awards you a title, and killing Sartharion with 2-3 drakes also awards bonus loot. (imo they should have made more bosses using this mechanic) In Ulduar (Released in 3.1) 11 out of the 14 bosses in that instance follow this same mechanic, so get used to it. While doing a boss the "easy way" will get you some gear and allow you to visit the last boss in the instance, going the extra mile will allow you to get both better gear and enable you to do the other bosses faster.
Farm loads of cash
If you don't have at least 1000g to your name, or slack even more and don't even have an epic flying mount yet.. you should definitely work on your cash. If you're a herbalist, skinner, engineer or miner it shouldn't take much imagination on how to get yourself some spare change by selling farmed materials on your local Auction House.
The best way to make money, is to "not" spend it. Don't buy crazy shit like the Traveler's Tundra Mammoth or any other 1600g mounts for that matter. You can buy a simple flyer for 200g and it'll be just as fast to fly as any other epic flyer, and land mounts are only 100g as well. There's even some free rare drop mounts if you're "really" cheap and only buy the skill. But the droprate is fairly low on most of those. The flying mount from culling of time is probably the only exception to this. (As it's doable daily, you can have it in 5 days tops)
If you're a tailor, enchanter, leatherworker, alchemist or blacksmith then I haven't got much better advice for you at the moment. Other than: Go do yer damn dailies. It's silly how people manage to buy empty the AH for 500-2000g worth of stuff every few weeks and then have the gall to complain that they're "broke" all the time and don't have cash to buy an epic flyer... Seriously, If you need cash don't spend it.
Play 3.1 on the PTR!
It's on the PTR, so it's available already for your enjoyment. You won't be able to really get anything permanent out of it though. It does help you discover / learn tactics for the bosses in Ulduar though. But, you'll also be bored with 3.1 sooner this way, and thus end up in the same situation waiting for 3.2 to arrive... Probably not a situation you're eager to be in, unless you're one of those no-lifes in the top-10 guilds world wide. I doubt any of them read this blog anyway.
Cap some reputations
While not immediately "useful", capping reputations in factions you use a lot will potentially save you a lot of gold in the long run. When you're friendly you get a 5% discount, 10% for honored, 15% at revered, and 20% at exalted.
If you later with to buy the Kirin Tor ring and it's upgrade in 3.1 at a price of 1000g, you'd be saving yourself a portion of that price at least. Do keep in mind that your regular HearthStone's cooldown will be reduced to 30 minutes though, so you'll probably find less of a use for such rings. Not to mention that Ulduar drops ilvl 226 gear, while those vendor rings are ilvl 213.
And then, there's repair cost. If you're not already exalted with wherever you usually repair at, keep in mind that you will have to repair your gear a lot, every single day. Those 20% add up in the long run. (Don't repair with bots if you can help it)
If you're really crazy you can even go all the way and get 40 Exalted Reputations to get a fluffy title for your efforts.
Farm 10-mans with alts
To kill boredom if anything, and keep people interested in the game.
The use of alts in relation to raiding is marginal at best, and with 3.1 even less so since your main raiders will be able to switch specs on the fly between bosses. Having your favorite healer or ranged dps disconnect mid-raid would be a lot less critical than it might be for you now. Still, if for example your healers have a decently geared alt for grinding money/herbs that would indirectly benefit your raid force. Or in combination with some alts and casuals you manage to do an "extra" naxx clear each week to help gear up raiders who missed the regular clear, or new trialists, then the effect is slightly more noticeable.
Everyone benefits, in some obscure way or the other. It's always useful to see all perspectives of the game as well. If you're always just healing, then it's hard to imagine what the melee dps has to go trough, and vice versa. You'll become a better player in the end.
Gear up potential recruits
Recruit extras, you never know when you'll find some unpolished gem that may turn into an amazing raider. Also, plenty of people will be "retiring" or quit playing altogether during long months of no content, they'll need to be replaced somehow.
If you don't have any actual recruits waiting in line, then you can always "sell" raid spots for your farm runs. You'd be amazed how many people are willing to pay 1-2K per item for those regular 25-man naxx drops that you're always cursing at and disenchanting because every regular player in the raid has already got them for 3 different specs. Put those purples to good use and gear up your faction while beefing up your guild bank for repairs in the near future. Not only can you get easy repair money this way, you could also find interesting players you may consider recruiting without having them go trough the whole apply and trial thing. Some players are actually quite intimidated by the thought of raiding, even though they may be exellent players. The best way to get them to apply is to ask them.
Quit the game, no no no, not permanently, just for a few hours or a day or two to alternate and expand your interest a little. Diablo 3 is in progress, which should make for a very interesting diversion indeed. However, in Valve Time it'll probably be done "When it's done". Blizzard has a hand in that as well, but they DO make good products.
Armorgames tends to have some quick and easy (fun even) games to spend your time with. Same goes for Miniclip.com and whirled obviously. Ever tried eyezmaze yet?
Also BvS, Dragon Tavern, Mr Tiki, Molehill empire or Urban Rivals if you like simple browser games. I also heard Magewar is back in a cloned form called reincarnation. I haven't gotten around to testing it yet, but magewar was pretty good for a text browser game.
And, not least of all igf is doing a 2009 Independent Games Festival awards thing. There's a few interesting ones on the list there. Be sure to try out Cortex Command, it's pure liquid win.
In short, there's plenty of ways to distract yourself until 3.1, and until 3.2 if 3.1 starts to bore you...
I've made a new poll on the right, how much have you done so far?
ps: Tagback to holy warrior's blog.