http://www.virtualbox.org/wiki/Changelog

Для Ъ:

* OVF (Open Virtualization Format) appliance import and export (see chapter 3.8, Importing and exporting virtual machines, User Manual page 55)
* Host-only networking mode (see chapter 6.7, Host-only networking, User Manual page 88)
* Hypervisor optimizations with significant performance gains for high context switching rates
* Raised the memory limit for VMs on 64-bit hosts to 16GB
* VT-x/AMD-V are enabled by default for newly created virtual machines
* USB (OHCI & EHCI) is enabled by default for newly created virtual machines (Qt GUI only)
* Experimental USB support for OpenSolaris hosts
* Shared folders for Solaris and OpenSolaris guests
* OpenGL 3D acceleration for Linux and Solaris guests (see chapter 4.8, Hardware 3D acceleration (OpenGL), User Manual page 70)
* Added C API in addition to C++, Java, Python and Web Services

+ много фиксов