Whew, been away for a while, and this thread has taken a new direction. Back at school now, so I have a lot less time to respond.
I think the space age will undoubtedly be ruled by governments, at least for the beginning. It's a fact of life - every time a new venue for civilization opens, it is spearheaded by the military. The government wants to check it out to see if it can use it for its own advancement. That's how it is right now, too - all NASA astronauts are air force pilots.
Once things settle down and the space age takes hold, then the corporations will roll in. Corporations are always looking for new ways to make money - call corporate space expansion a sort of outsourcing-taken-to-the-next-level. Hell, civilian transportation to space will have to be done by businesses.
Also, I would not cite Russia or China as realistic contenders for the "colonization race" in space. Russia certainly not - the country's economy and military are in total chaos, and right now they are just having trouble keeping them from falling apart completely, let alone trying to make new strides in the field. China, on the other hand, has way too much building to do at home to think about beating us into space. They just launched their first satellite, what, like two or three years ago? We have hundreds up there. There's just no contest, the U.S. will have to be the first up there, unless the economic situation changes radically in the next few years.
Still, I just don't see space as a priority right now. Too much is left to be done down here. Going up into space and forging a new future and forgetting your past to become part of the great pioneering of humanity into space sounds romantic, but the fact is it will only be avaliable to a small minority for many years.