Oliver Rist of InfoWorld recently posted this article -- "Vista Hardware: What to Buy Today for Tomorrow's OS" ( http://weblog.infoworld.com/smbit/archives/2006/06/vista_hardware.html )
I would not put off purchasing PCs. We've had to do that for several years now for budgetary reasons, and it has really put us (me!) in a big hole. I also agree with Dale, I'd personally shy away from jumping right into Vista. I'd look at buying machines with at least 1 GB RAM (preferably 2 G

, a dual core processor wherever the best price break is, and a video card that will support running Aero with at least the 128 MB RAM (preferably 256 M

. I'd personally be surprised if you'd find any new system that would not meet the hard disk space requirements. If you can afford the extra RAM for both the main system and for the graphics card, I'd get it now. While it is fairly easy to upgrade either if your comfortable doing those kinds of things, it means that you have to be willing to do it when the time comes :-)