In all honesty, I don't think Google would do much to try and control Valve. We've seen Youtube post Google buyout, and not much is different over there. The one thing I think would change, is that Valve would have a lot more money at their disposal, as well as a wealth of new internet resources to be able to get a hold of. I think that's why this would be a good thing for us gamers, as well as both Valve and Google.