If you have downloaded the VS2008 Beta2 VPC from MSDN you need to be aware that this VPC is due to expire on 1st November, much earlier than planned.
Jeff Beehler’s blog [VS2008 Beta2 VPCs expiring prematurely] has all the details.
If you’re current using the VPC image you need to consider taking steps to secure any data you have in the image asap.