There is always the Utgarde castle that could be a candidate. There's plenty of room to develop the San'layn and Darkfallen varmpire elf dudes as they appear quite a few times throughout LK and specifically in UK. At the end of UK Annhylde the Caller comes and resurrects the last boss too. While she is most certainly working for Arthas, there's a lot of room for development for either a Utgarde raid or simply an expansion of those fellas in Icecrown.

Don't forget the possibility of adding a new 5-man in 3.2. We could still do Grim Batol/Gundrak if one of them is a 5-man. My bet is Gundrak as a troll raid instance, and Grim Batol as a Caverns of Time 5-man instance, perhaps foreshadowing a Blackwing raid in the next expansion.

Shouldn't we be able to look for ourselves by not updating the PTR all the way? What build was it removed in? Related question, is there a working mapviewer/sandbox for the PTR?

I don't think the next raid will be with trolls, it doesn't flow at all. Trolls do not seem to be part of the main story arc outside of what we already have seen. Either its going to lead into Icecrown Citadel, or its not connected at all and could be anything. I had my money on Yogg being the new raid and something else at the end of Ulduar before, but I'm not sure would be between Yogg and Arthas.

Are we even certain there is going to be a raid in 3.2? I honestly would not be surprised if blizzard wants WotLK to have only three raid instances and three tiers of content instead of the 4 we had in classic and TBC.

I believe blizz said there would be a raid after Ulduar and before Icecrown.

Yeah, the main problem is that there are no real obvious loose ends for 3.2 to resolve, besides Arthas himself. The Twilight Dragonflight story is exceedingly tangential, Blizzard has gone out of their way to destroy anything that could possibly tie into an A-N zone, Gun'drak would cause a million facepalms from the playerbase.... so it seems like Blizzard may possibly try to tie up some random loose end in Azeroth (Timbermaw Hold!!1), or possibly open up a new plot thread leading to the third expansion (which might be why they're tight-lipped about the content at the moment. Perhaps they're waiting for a Blizzcon announcement?)

The only other plot thread I can think of would be Mal'ganis', but I can't see that tying into any raid, unless we're going to invade Xoroth or something random like that.

The "plan" according to Tigole was laid out specifically at Blizzcon in regards to having new raids in 3.1 2 & 3.

With Ulduar being in 3.1, and Icecrown being in 3.3, and 3.2 was supposed to be super duper secret, so we all just assumed Azjol-Nerub since there was all that speculation from Brann about retaking the underground spider kingdom in the RPG books, and because in the Frozen Throne you spend like 3 missions down their guiding Anub'arak & Arthas through it.

Then of course we learned about the whole tie-in to the Night of the Dragon book with Grim Batol and Deathwing being alive and the Twilight drama, so now we're learning toward assuming it's a Grim Batol raid.

But of course it doesn't stop there, because some of us hate Trolls, and troll raids, and Blizzard hasn't had an expansion yet without one(regardless of the fact there's only been one :P) so the really dark and gloomy people(I love you all) are assuming the super secret raid will just be another troll raid.

Then there's the Gilieas theory, which is my own, and has absolutely no basis, but I mean, it's super duper secret what's going on back there, and Metzen said snipers would take him out @ Comiccon in New York if he talked about Gilineas, so who knows!

Further insane theories include Ner'zhul possessing Malyagos' dead body since Arthas kicked him out, Dalaran crashing some place and becoming a Fallout 3 type zombie raid, and of course there's always Caverns of Time: Fall of Dalaran where we team up with Arthas/Kel'Thuzad/Archimonde to destroy the original Dalaran, again this is all ridiculous speculation because Blizzard is so tight lipped about what the heck they do there.

Unlike the other temples, the quest text for Tyr's says "No indications of struggle are present.". The other temples are all destroyed, corrupted or show signs of a struggle. I think he got the hell out of there for whatever reason, and Blizzard hasn't forgotten about him.

Seeing as how he is the character associated with order, he could easy show up in almost any raid, quest or cut-scene to help the heroes "restore order" and kill whatever baddie is messing with Azeroth.

I could see it playing out that his job was to maintain order on Azeroth and he could just go anywhere rather than being confined to the Northrend area which could make him appear somewhere such as Uldum. It could also end up that he died in the past to something.

What about the rumors about a coliseum raid, related to the new Argent Tournament: MMO-Champion BlueTracker - Argent Tournament Timing?

At least MMOC thinks it will be a new raid: Source

I think a 3.2 raid is going to have us back in Outlands, or something similar to attack the home of the dreadlords, with a second shot at Kil'Jaden maybe. There have been hints as far back as blizzcon '07 that they had planed out raids to legion worlds for TBC but went with Sunwell instead. We have the events of wrathgate with Vermathas attempting to summon someone unknown, a few loose threads surrounding the lost windrunner sister, Also Mal'Ganis showing up at the end of a Icecrown quest chain. Perhaps they will tie Arthas in to provide a few threads to a 3.3 Icecrown raid.