I’m using Vegas 9, but no HD editing (yet). I currently have an AMD Athlon 64 X2 4200+ / 2.2 GHz running XP. I am thinking about getting a new computer with Windows 7 and an AMD Athlon x4 620 / 2.6 GHz quad. Will I see much of a difference or should I save some more $ and buy a computer with an i7?

If your current machine is doing what you need it to do I would wait till you go HD and then get the i7 or whatever is the latest and greatest machine out there. I am running Vegas 9 with an i7, doing HDV mpeg 2 and am really impressed with the render times using all 8 cores. It was definitely worth the upgrade from 4 cores to 8.

I tend to agree with this post... The i7 for editing is really the only way to go... They'll only get faster and cheaper.. save the $$, wait until you need it, and don't be affraid to spend just a bit more than you'd like because your system will last you quite some time..

Jon