If your looking for good deals on software and you have a good enough machine to run the games then steam is the way to go. I personally prefer the console platform, however, the expenses can pile up on you especially when investing in an expensive capture card.

Oh the names, omg.

I would say use Steam for a bit then get the 720 as soon as it comes out. The 720 will probably last you a couple of years, and you don't need to worry about things like OS compatibility and things like that because all the stuff you need is right there.