I would say, stay away from new software/hardware for a few months because it's usually pretty buggy, not to mention the fact that it just doesn't have the driver support most newer hardware componets need. I know Vista, at the moment, still has a lot of hard-to-find drivers. It shouldn't really slow anything down, per-se... it does have a lot more overhead for the OS, but if you have a 64 bit CPU, you might actually see better performance..... if you can find the drivers you need.