The new automatic update feature for VMware Fusion helps to keep Fusion updated easily.
Improved 3D & Video Performance: Improved WDDM driver and 3D backend improvements speed up 3D applications from 20-80% on Mac OS X Snow Leopard. Video playback with Windows Media Player on Windows Vista and Windows 7 is greatly improved as well. Try it, you will love it!
Ubuntu 9.10 (Karmic Koala): Full support for Ubuntu 9.10 32-bit & 64-bit editions. Just like other Linux virtual machines, they support copy and paste, drag and drop and even Unity!
Even More 64-bit Support: Networking subsystem is now 64-bit native to match 64-bit core engine released initially with VMware Fusion 3 (vmware-vmx).
Easier Move to VMware Fusion: Import standalone VHD virtual disks and Parallels Desktop 5 virtual machines into VMware virtual machines.
Improved Resume Times: For those users who suspend their virtual machines, they reduced the time required to resume your virtual machines.
Check out the announcement post here