CaptainGyro: wtf no they won't. Did you just really say that they would claim that being Windows only increased sales? You're arguing just to argue
Kristian: Sorry let me rephrase that: They will claim that it was the DRM that increased sales on this bundle due to less piracy.
Are you claiming that anyone would believe that DRM is a marketable asset? Everyone at that table would know the reason this would be the best selling bundle is because these are big-name, highly marketed AAA titles. The addition of the Steam requirement would, if anything, only hurt sales.
Trust me, the decision makers at EA or whoever know the difference in market presence between a title like Saint's Row and a title like Voxatron.