Howtogeek posted a guide about installing Windows Home Server Vail Beta on VirtualBox

If you dont have an extra machine or are an early adopter who wants to test out Vail, creating a VM is a good choice. To complete our series of installing WHS Vail Beta virtually, we look at installing it on Oracle's VirtualBox.
We've previously shown you how to install WHS Vail on the following VMware Products:

Workstation
VMware Server
VMware Player

Today we complete our Vail VM series and show you how to install it on Oracles free VirtualBox.
Note: You will need to install VirtualBox on a 64-bit Windows System that supports hardware virtualization. We've read some articles that you can install it on a system without Hardware Virtualization, but haven't been able to confirm that. For best results make sure the Host computer supports Hardware Virtualization.
To check if you're system is capable of Hardware Virtualization you can use either SecurAble or the MS Virtualization Detection Tool?both are free and easy to use utilities.

  How to Setup and Install Windows Home Server Vail Beta on VirtualBox