There was a list that EA posted about which digital retailers would be selling Battlefield 3; unfortunately the list was taken down, but Joystiq was able to get a glimpse of it and Steam is nowhere on that list. Steam not being on the list most likely is due to the little scuffle EA and Valve got into.
The story is that Crysis 2 was taken down from Steam because,
Steam has imposed a set of business terms for developers hoping to sell content on that service – many of which are not imposed by other online game services. Unfortunately, Crytek has an agreement with another download service which violates the new rules from Steam and resulted in its expulsion of Crysis 2 from Steam.
Crysis 2 continues to be available on several other download services including Origin.com."






