Vista will run OK on 1GB of RAM. Because 1GB is standard now, if not 512Mb, and microsoft would be in trouble if it didnt run on your average Dell pc that consumers buy, wudnt they now ?? I for one will not be buying Vista, it is imo not good enough yet, the support for games and programs is to limited, , and the security is overpowering on the PC.
I may have to buy for new DX10 games though, which will be a real shame because Windows XP is fantastic for me at the moment... It does what you want it to do, and very well, No thrills just a rock solid easy-to-use Operating System, that still remains functional and enjoyable.
Vista is for me at the moment to much a designers item so to speak, Its not a rock solid gameing OS, infact it has lower FPS in games in many cases, its very buggy, rushed and is to protective. It has many niggles that i will never use, and will be sure to just go wrong somewhere down the line.
If they released a watered down version of vista, (Imagine xp with a Service Pack 3) and it had DX10 Support iwould buy it, when i have to.
Furthermore its far to expensive.