For what it's worth, I started with a older GeForce 7950 GT, P5 3.4 Ghz, Windows XP, and 3 gigs of RAM - basically a top end system (5 or 6 years or so ago). I couldn't even get it to run the benchmark tool completely. If I waited until the end I'd see a score of around 300.
Figuring my main problem was my video card, I upgraded to an ATI HD 5850 for just under $300 bucks. With the video card upgrade I was able to play the beta "ok" with low settings but I noticed that my CPU was always between 90-100% utilization. After installing the new video card my benchmark was around 1200 - playable on low settings but you'll still feel the pain.
Well, tonight I bought a new mother board and CPU, an i7 950. Upgraded to Windows 7 64 bit and loaded up with 6 gigs of some pretty spiffy RAM. What a difference! I reran the benchmark and couldn't believe the difference. I'm now scoring 6500+ on the benchmark and it runs so smooth - at this point my CPU and memmory are all running at factory specs, I haven't gotten around to over clocking yet. I can't wait to try the retail version tomorrow! Hope the info helps.