Steam is now offering
online sales and downloads of Crysis Warhead, Crytek's first-person
shooter follow-up. In a bit of a surprise, this precedes the game's
international release, which is tomorrow (story). They are also
offering Warhead as a bundle
with the original Crysis.
Crytek probably just didn't want to go through the trouble of using Steams version of copy protection and went with SecuROM, also if they had released the game through Steam without protection it would have made it easier to crack.