A number of tips came our way this morning saying that Crysis 2 has disappeared from the Steam store -- sure enough, that does indeed appear to be the case, with a search for Crysis on Valve's store bringing up nothing but Crysis, Crysis: Warhead and predecessor Far Cry . Searching for Crysis 2 brings up nothing but the original Crysis, and searching for "Crysis 2" as an exact match brings up nothing at all. This situation is worldwide.
Crysis 2 is, however, still available from Origin.com, EA's recently-rebranded digital distribution store, formerly the EA Store and EA Download Manager.
Mysterious -- but likely simply due to EA desiring to bring more business Origin's way for new(ish) releases, rather than splitting revenue via third parties. We've sent EA an email to try and find out the official line on what's going on and will update this story when we hear back from the company.