During last year's Blizzcon it was announced that profession specializations would be removed. Even before the Cataclysm Beta ended, I had plans to review specialty recipes and document any changes. I certainly never found anything obvious, but I didn't have time to visit every specialty trainer in the far corners of Classic Azeroth. I've tried to do some poking around on the Live realm with mixed results. However, with everyone rolling new toons (or changing professions on an old toon) I thought I'd try to lay out what I've uncovered so far.
Tailoring never had much of a specialty system, just the ability to create bonus items when making one of the three special, high-end cloth types. This doesn't seem to be working anymore, I made all three Wrath cloths and didn't get a bonus cloth on any of them. I don't know if it's supposed to work at this point, but it doesn't seem to be. Be sure and let us know in the Comments if you've found otherwise. One thing I was able to discover is that the specialty restrictions have been removed from the Burning Crusade recipes, which were the only recipes that required a specialty. These recipes aren't learned from a trainer, but the vendor recipes have been modified to allow any Tailor to learn them.
Alchemy uses a similar system to Tailoring, where you pick a specialty that allows you to "proc" bonus items that you craft in your specialty area. You must do one of three quests in Outland to select a specialization. You can also switch specializations by visiting your old trainer to unlearn his specialty, then the new trainer to accept theirs. This process costs 150 gold and it hasn't been changed since Burning Crusade.
Leatherworking is pretty dysfunctional at the moment. Every trainer I've visited has been converted to a regular trainer with no specialty recipes available at all. Only three of the old specialty recipes appear to have survived this process: Dragonstrike Leggings, Blackstorm Leggings, and Wildfeather Leggings and these no longer require a specialization, although they are still Bind on pickup. The level 70 epic sets have been removed and many of the classic specialty recipes also seem to be gone. The specialty trainers in Dalaran have been converted to normal trainers. Sara Tanner, Thorkaf Dragoneye and Peter Galen are gone, while Brumn Winterhoof and Se'Jib have been converted to regular trainers and Caryssia Moonhunter is now a quest giver. Currently there's no way to train Leatherworking recipes that were part of a specialization except for the three listed above.
Also, the ability to switch Leather specialties appears to be broken. I went to Tanaris to see if it was possible to change professions and perhaps pick up recipes that way. The book will show you a list of specialties, but does nothing when you click them. For Leatherworkers, this book just doesn't work.
Blacksmithing appears to be in a similar boat. Many of the specialization recipes from Classic WoW and Burning Crusade are gone. The trainers who used to teach them are now just regular Blacksmithing trainers. I visited Ironforge, Shattrath City and Dalaran and they've all been converted to normal trainers. In fact, my recipe book doesn't even designate me as a Weaponsmith any longer. I also visited the specialty weapon trainers in Everlook. They're still there and their dialog windows seem to indicate that they will train you in a weapon specialty. However, they have no options for actual training. One of them did offer me a quest, which led to another quest from the second trainer and then the third. These quests don't appear to be related to Blacksmithing, unfortunately.
Engineers can still change specialties and learn recipes from their chosen specialty. The specialty trainers that were available before are still working. Also, the book in Tanaris that allows you to switch from one spec to the other is functioning correctly for Engineers. You're still unable to learn all recipes across specialties as announced at Blizzcon 2009, but at least the specialties are working in some capacity. This puts Engineering on better footing than Blacksmithing and Leatherworking.
I will continue to keep an eye on this situation, it's still possible that some of these problems will be corrected in a future patch. For now the state of specializations appears to be in flux and depending on your profession you may not be able to do much about it.