What are you talking about? Portal, TF2, and HL2:EP2 came out in 2007, L4D in 2008, L4D2 in 2009, Alien Swarm in 2010, Portal 2 just a few months ago, and they're working on DOTA2 and HL2:EP3 (or maybe just HL3?) right now. They're an active company and will remain so.