Received this two days ago from Microsoft:
“We are pleased to announce that build 5472 of Windows Vista is available for your testing!  This build contains numerous fixes since build 5456 and demonstrates significant progress on customer feedback since Beta 2.  Most notably a new Nvidia driver has fixed many reported issues and recent changes should provide improved Windows Media Center performance.  You should be aware though that this is an interim build and while significant testing is always done, it has not undergone the rigorous testing that Beta 2 did.  We believe that most people will find this build improved but as with any interim you may encounter issues we do not yet know about.  Please move up to this build from any previous build and tell us about any problems you encounter.”

What we ask that you do with this build:

Upgrade Beta 2 – Beta 2 to RC1 will be a supported scenario.  We need your help finding bugs we need to fix that may impact our TAP customers that have deployed Beta 2 and the Preview Program users who may upgrade.  We do not ask, nor do we recommend, that you upgrade any other build besides Vista Beta 2 or Windows XP to this build.”