The purpose of this post isn't to detail all the changes, there are too many to go into here. What I want to discuss is the effects of some of these changes on recipe availability. The changes wrought in Cataclysm have created some holes that crafters may want to be aware of. Market speculators might want to try and capitalize on some of these changes. This new information is not yet posted on my web site but it will be updated when I wrap up the 4.0.6 changes.
Recipes with NO Vendor
Grilled Squid (Moved to the trainer in 4.0.6)
Nightfin Soup (Moved to the trainer in 4.0.6)
Poached Sunscale Salmon (Moved to the trainer in 4.0.6)
Spotting Yellowtail (Moved to the trainer in 4.0.6)
Recipes Missing from Alliance Vendors
Recipes Missing from Horde Vendors
I have to say that some of these items are unfortunate casualties. The most significant is Shadow Oil. This ingredient is used by other professions and the loss of it appears to be causing some frustration in the community. Naturally anyone who leveled Alchemy prior to Cataclysm will have the recipe, but that doesn't appear to be helping the supplies.
Cooking has been hit pretty bad, losing ten recipes on the Horde side (8 for Alliance). The two additional Horde recipes are particularly problematic since they were added not too long ago to provide a leveling option for non-Fishermen. Other recipes that I'm sad to see on this list are the Deviate patterns for Leatherworkers and the Deepdive Helmet for Engineers. The Deviate cloak was the best of the three cloaks available in its level range and the Deepdive Helmet had great utility.
There's probably some opportunity for new markets here with cross-faction selling of these recipes. I think the JC patterns are good candidates for that. The two Bear recipes will likely be a solid item for Horde buyers. And I think every Alchemist should consider making Shadow Oil if they can. I've no doubt you could get a primo price for something that can't be learned anymore.
For now I'm not removing any of these recipes from our listings, I'll simply note that the vendors are missing. It's possible that some of them could be resurrected, or if nothing else we can provide useful information for networking with other crafters. I don't deny that some items probably could be pruned from our recipe lists with no ill effects, but I'm not convinced that's what happened here. I hope Blizzard will look at putting some of these recipes back into play, or if nothing else give us an official statement on their status.
** UPDATE ** Just found a few of the Cooking recipes on the trainer, apparently they are being moved in 4.0.6. I've made a note of this in the Missing list :)