Kevin,
Fusion is running fine on my machine:
Dual Core 2.7
1GB RAM
The only problem I'm having is that the Fusion window will not maximize. I run dual monitors, but I haven't thrown it over to the other monitor, but then I haven't got to spend much time working with Fusion either.
This is/ was just a minor annoyance and barely worth mentioning. I would give you better system information, but I have Fusion installed on my Home Office System and I'm not currently there.