I purchased a VMWare license just a month before the 'free upgrade' window. So I would really like to try out Fusion 4.0 before I plonk another 50 bucks for the 'upgrade'. Can I install 4.0 trial and expect the 3.x to be still around? Or does 4.0 overwrite 3.x?

In either case, do the VMs created in 3.x work straight off the bat or do I need to do a 'one way' upgrade for them to be usable in 4.0?

I am still using OSX Snow Leopard.