Well the do seem to be recruiting
WotC have recently recruited Jesse Decker (of Dragon fame) to work for RPG R&D. And hiring people is not usually considered a surefire sign of the sky falling...
As to who is left, I don't really know. Tweet still is, Wyatt still is. Collins, evidently, Richard Baker. And probelby more than that.
Me, I was surprised they had so many people on board at the first place. In my opinion a RPG company should only have a couple of line developers and a couple of inhouse writers, and a couple of editors, art directors and a full time concept artist.
The majority of the writing and illustration should go to freelance people. That makes it easier to grow and shrink with the ebb and flow of demand.
In my opinion, and with rampant speculation from me, prior to the layoffs (some one year and five months ago, and we're still taking that as a sign of the sky falling. Or at least the roof
), WotC RPG R&D was way to crowded to be a viable business.
Or even a viable development studio. Inhouse people tend to have opinions on things, such as the direction of D&D, and if you have something like 20 knowledgable people arguing about what is best for the brand, AND you have to keep them busy doing things to earn their wages, you end up with a game line that is diverging in brand integrity. Case in point being Ghostwalk, a nice book, but not really a strong brandbuilder or a huge source of income for D&D. Probably a result of differing philosophies.
Oh, the horror trying to manage that group of people!
So keep a core team, and farm the rest of the work out. The trick of course is to keep the right people.
WotC adjusted to a setup which to me looks more healthy, and which incidentally provides income for the community's growing number of freelancers. In my book that is A Good Thing™.
Cheers!
M.