- Support for 64-bit guests on 32-bit host operating systems
- Experimental 3D acceleration via OpenGL
- Experimental LsiLogic and BusLogic SCSI controllers
- Full VMDK/VHD support including snapshots
- New NAT engine with signiﬁcantly better performance
- New Host Interface Networking implementations for Windows and Linux hosts with easier setup
Of greatest use to me was the new host interface networking. This used to be a pain to set up in previous versions of VirtualBox (actually I just gave up on it); now it runs without any hitches whatsoever. This means I can now run an accessible server as a VirtualBox guest.
The VMDK support means that I can now run VMWare guests on VirtualBox. I still have to try this feature, though.
And the misses? Just one, for now: the virtual disk cloning doesn't work. It results in a cloned disk image that is much smaller than the original. For the moment, I have to manually copy the disk image and set the UUID using
VBoxManage internalcommands sethduuid myoriginal.vdi
I hope this gets fixed soon.