Vmware Fusion 3.0 (Full Aero Support with Windows 7)
Just grabbed the release of VMWare Fusion 3.0 which was released today at Midnight.
Full 64 Bit support under Snow Leopard, and full support for Aero Graphics with Windows 7.

NOTE: If you are wondering how to turn Aero on for an existing VM? Make sure you change the VM type to Windows 7 from Server 2008 or Vista. Install the new VMWare Tools to update the drivers. After a reboot make sure you go into the computer properties and update the windows experience rating. This will take a few seconds and when it is done you will have all the Aero goodness.
your advice doesn’t work!
It might be the mac you are running on has an older integrated graphics card which doesn’t currently support full Aero. Take a look at the VMWare site and see what the minimum specs are perhaps?