Because Crysis and Crysis: Warhead are published as part of the EA Partners program (the same way The Orange Box is) Crytek has more control over their game then usual. EA has nothing to do with Steam versions of Crysis and Crysis: Warhead - it's all between Valve and Crytek.

Nope, that's not what I meant. :)
I don't know what future will bring, but rest asured that we all would love to see games from EA on GOG.com... games such as Dungeon Keeper, Command & Conquer, SimCity, System Shock or Wing Commander to name a few. All we can do is wait and hope for the best. :)