VMware Fusion 1.0 was and is great. I have always been a big fan of the product. Fusion 2.0 is promising to be even better! You can get your first look at what the finished product will look like with the release of RC-1. The upcoming new version (and currently in the release candidate) promises embeded McAfee AntiVirus, improved localization options, much improved Unity between Mac and Windows, multiple snapshots, vastly improved graphics capabilities (including HD video playback), quad-core VMs, the ability to virtualize OS X Leopard Server, and more.
The RC-1 is available to download today. However, it will replace your 1.x, so only take the plunge if you like Beta software. Also, owners of 1.x can look forward to a free upgrade to 2.0 when released.
One would need the Mac Pro to use a quad core VM. That would be really cool, though.