Yeah... sadly I will probably be in the same boat.
My PC is definitely starting to age, and I doubt it is going to run UT2K7 at playable frame rates (if Quake 4 was any indication, I'm pretty much screwed).
Problem is, I've been running VERY tight financially lately and it's pretty tough to justify to the wife: "Sorry honey, you have to buy the off-brand Mac & Cheese so I can afford to plop another gig of Ram into my online gaming beast."
I'll see how the demo runs on my current hardware first, but if it ends up being a slide show, there isn't much point in buying the game until I can upgrade.
...
Unless it has a REALLY badass manual... Then I might buy it anyways. dunno.