Another problem for BiS fever is the new Raid Finder. By running easy mode content, anyone can get items which bridge the gap between dungeon gear and normal mode raid gear. There are more options now for gearing up than ever. I think all of these things are affecting the BiS market, mostly in a bad way. I suspect the only folks who really care about getting BiS items right now are guilds working on Heroic Dragon Soul. And we can assume that those folks very likely have all the same recipes you have (or access to a guildie who has it) and will have the item made for them at the cost of mats. I think this leaves a pretty small pool of people who will buy a crafted BiS item on the auction. Each week that goes by reduces the number of players who are still looking for BiS gear.
On a slightly different note, my personal problem with the Dragon Soul recipes is that they overlap with Valor gear. Half of the new recipes are for bracers, which players can get more easily with Valor points. While we can argue the merits of itemization, most players will go for the easy option, which in this case is the Valor bracers. That means realistically the only crafted items we can expect to sell are the pants. Pants which have to compete with Raid Finder set tokens. I don't know about you, but I'd have a hard time paying thousands of gold for 397 pants when I can get 384 pants in LFR *and* meet my set bonuses. I really think Blizzard should have done a better job of using crafting recipes to fill the gaps that aren't covered by other sources. Personally I'd prefer to see more trinkets/rings/necks/cloaks on the Valor vendor with things like boots/belts/bracers going to crafters.
That said, I think there is a place for crafted items in the current market. That spot is in the gap between heroics and the Raid Finder. It takes an item level of 353 to run the new heroics. From there you have to jump all the way to 372 if you want access to the Raid Finder. Most players are impatient and want to get through that as quickly as possible, which can be maddening if drops don't go your way. Right now I'm working on my hunter and I can tell you that the weapon slot is infuriating. There is only one item we can use and it's from Sylvanas in End Time. Since Sylvanas is in rotation with other bosses, we can't even be certain she'll spawn. I'm selling 1-2 Witch Hunter's Harvester's a week, probably to frustrated hunters and kitty druids who get tired of farming End Time.
I suspect there are other niche items that fall into this same category, so I would do a bit of research on it. Check the recipes you have in the 365-378 zone and figure out who might wear them (WoWPopular can tell you what the most popular specs are for each class). Use sites like GuildOx.com to check loot rankings for the item you want to sell and see how they fare against dungeon and VP/JP options. If you have a recipe with little or no competition outside of raids, that's likely to be a winning item. What you don't want to do is craft an item that competes with multiple heroic drops or any of the quest items available from the Twilight heroics. For example - Warboots of Mighty Lords is probably not a strong seller because players can get boots that are almost as good from the quest in the Well of Eternity or spend Valor Points and get better boots.
Bear in mind that while the action in the BiS department may not be great, there are some viable markets for gear crafters. Transmogging is still pretty active right now, and I find I'm spending lots of crafting time providing those great older items. I'm still selling sets of Imperial Plate as fast as I can make them. The good thing about making crafted gear for transmog is that not everyone has all of the older recipes - that gives us a niche. Not everyone wants to spend the time farming older materials, that's another plus for us. At the end of the day does it matter if I made a 2k profit off you from a BiS item or a classic transmog set? Not really, I still have your gold and you have the shiny. I can live with that =)