I've been experimenting quite a bit with my new macbook pro and have run into significant performance issues with VMWare fusion as well as running natively from bootcamp.
My three scenarios are:
1) Native booting from bootcamp (16gig, SSD)
2) Native booting OSX, VMWARE fusion running from bootcamp partition (8 gig ram for vmware plus 4 of out processors)
3) Native booting OSX, VMWARE fusion running from files on native OSX partition (SSD) (8 gig ram for vmware plus 4 of out processors)
I don't have enough space to try all these at the same time but I'm suspicious that number three is significantly faster than either 1 or 2.
I've found that in both 1 and 2 (which is what I have loaded now on my computer), doing things like building large projects with visual studio 2010 boggs down, where as on my Lenovo W520 running on the same type of SSD, I don't get bogged down. I am surprised native bootcamp is any slower, but it seems to be.
Any thoughts appreciated.