I now have a machine up and running with the new Windows 7 Beta installed. I'm running it on a 6 year old IBM T30 laptop with a 2ghz P4 processor and 512 MB of RAM, and it's not doing too bad. No WinFS though, which saddens me. Here's a screenshot of the desktop:
It's activated, and I'm even getting Windows Updates already. Just to answer a few questions that I know are going to come up:
Yes, you can upgrade directly from XP to 7 without formatting. This machine had XP on it previously, and I tested it.
No, 1 GB of RAM is not the minimum. This machine had 256 when I started, but during the first attempt I got an error stating that I must have 512 MB to continue. With no applications open, the system is using about 280 MB of RAM.
I have only installed Firefox so far. It's working well. I am installing the software for my blackberry, and next will be iTunes. I don't plan on really using iTunes much, since it's such a resource hog, I just want to make sure it works.
My only complaint so far is that this laptop has an internal bluetooth card which Windows 7 has not picked up.