I bought VMWare 4 and 10.7 and I think the problem is that both of these items are buggy as Kickstart 1.0! :-)
I felt that 10.6 with the latest patch was one of the most stable Operating Systems I've ever used. When I upgraded to 10.7 it was a disaster. I have found so many bugs that I wish I would have waited to upgrade. At this point, I think 10.7.5 might be usable.
I think that VMWare 4 is also buggy and I hope 4.02 or 4.03 will fix these issues.
However, having both VMWare 4.01 and 10.7.1 is a real treat...
I tried out Parallels 7 and it seemed very nice but I had purchased VMWare before so the upgrade price was very, very cheap.
So far I can live VMWare 4 but 10.7 is driving me crazy!
-P