No, this is not some post about how we should all just get along...
I've been a Parallels user since day 1 of owning a Mac, more or less. I've tried the nw VMWare Fusion Beta, and although it seemed to work OK, I had no real reason to switch. Until perhaps now.
Unity is VMWare's answer to Coherence - the technology which Parallels employs to display a PC window as if it were a Mac window. However, Unity takes it up a notch or two. It also works with odd-shaped windows, such as Windows Media Player. You can use Expose and have all of your PC windows behave just like Mac ones. There is direct access to the Start bar from the Mac OS X menu. And my favorite - you can permanently dock a PC application in the Mac toolbar!
I'll be interested to see how this all plays out, as I suspect some sort of announcement will be coming at WWDC next week.