The Tech Report noticed a comment from Valve that reveals the company may no longer make isolated single-player games:
The interwebs are buzzing with news that Valve may be finished with single-player games, at least as we know them. Oh, my. The claim comes from journalist Geoff Keighley's The Final Hours of Portal 2, a $2 iOS app that takes a behind-the-scenes look at the development of Valve's latest opus. In the iDocumentary, Keighly says the sentiment came directly from Valve head Gabe Newell and project manager Erik Johnson. Kotaku has the goods for those without iOS devices.
"Portal 2 will probably be Valve's last game with an isolated single-player experience," Keighley wrote in Final Hours, "What this all means is something Newell is still trying to figure out."