You can download the binaries here.
Please do NOT open bug reports at http://www.virtualbox.org/wiki/Bugtracker but use our VirtualBox Beta Feedback forum to report any problems with the Beta. Please concentrate on reporting regressions since VirtualBox 4.0.10 / VirtualBox 4.1 Beta 1.
The following items were fixed / added since the VirtualBox 4.1 Beta 1:
- VMM: fixed a Beta 1 regression which prevented certain guests from booting
- VMM: better out-of-memory error reporting under certain circumstances
- GUI: display CPU cap in the VM details page
- WDDM: serveral fixes
- Storage: fixed possible data corruption under certain circumstances with VHD and Parallels images
- Storage: introduced non-rotational flag for hard disks for optimizing the performance with modern guests (e.g. Windows 7 will not automatically defrag the disk)
- Floppy: make unmounting a host floppy disk work
- Guest control execution: fixed documentation + syntax diagram.
- Solaris hosts: Host-only/Bridged networking fixes
- Solaris guests: fixed automounting of shared folders
- Linux installer: fixed compilation of the vboxpci module if DKMS is not installed
- Windows Installer: fixed automated VBox Python API installation.
- Windows hosts: fixed a BSOD in the new USB code under certain circumstances
- Windows hosts: use Qt 4.7.3 including Oracle certificate
- Experimental support for PCI passthrough (Linux hosts only)
- Sources: fixed USB 2.0 support for non-official builds
- Documentation fixes