I had an idea, maybe not a particularly good one, but an idea. I'll advertise this on the raid and dungeons forums in a few days probably, but I'm starting slow here. I've always liked raiding. I like learning new encounters and in the end I liked coming up with my own (not even just raids.) I wondered to myself if anybody else liked coming up with encounter designs as well. Or if anything, just saying "Man, this fight would be much funner if X happened." Hell, I co-built an entire Campaign for Dungeons and Dragons, I wonder if anybody else wants to share something like that.
Well, if you are creative and want to share boss ideas with like-minded individuals, head on over to http://www.abaddongate.com/ and get designin.' That url will change eventually. It'd be awesome, if it is popular enough, to have contests and stuff! I figured a forum just makes the most sense for a resource such as this. (And I tried to find one like it first.) It's still not quite done or anything, but it works.
I anticipate a million Deathwing designs. Regardless, just have fun with it, there's no real official guidelines or anything yet, just flex your creative muscles.