DirtyLove]honestly i see from that list is a buncha people who made serious fail career moves.
Only company that has failed is Hellgate Londons. Torchlights working on a sequel, and of course arenanet is about to release the most successful mmo thus far of 2011-2012. If by successful you are going by how many people prepaid/preordered.
A lot of the smaller guys have scattered throughout the gaming industry, but that would have happened anyway with the hundreds of layoffs blizzard keeps going through year after year.