matt@lappy:~$ VBoxManage --version
4.0.8r71778
matt@lappy:~$ VBoxManage list extpacks
Extension Packs: 1
Pack no. 0:   Oracle VM VirtualBox Extension Pack
Version:      4.0.8
Revision:     71778
Description:  USB 2.0 Host Controller, VirtualBox RDP, PXE ROM with E1000 support.
VRDE Module:  VBoxVRDP
Usable:       true
Why unusable:
matt@lappy:~$