Soonjai: Who says that you need to upgrade your machines? My PC isn´t the newest one, but I never had trouble running anything. At the moment I play Metro 2033, I maxed it out, but I need to lower the resolution to 1280x720 to have a framerate that is always playable, same thing goes for the Battlefield 3 SP and lots of other newer games, and I don´t feel the need to upgrade anything. I can play my games and watch my BluRay Movies without any trouble on that thing and I don´t care that much if I need to lower the resolution and / or some graphical details.
We're talking about when the new machines come out, dude. If they have the specs several sites have rumored they do then we're talking 8GB of RAM and a brand new GPU, plus a damn good CPU and SSD storage.
I have 4GB of DDR2 RAM, a 2 year old GPU (GTX 480) and a 4-5 year old CPU (Q9550). I would surely need to upgrade to run things at a good resolution and framerate. Do you remember Oblivion?