In her Blog yesterday Heidi Hewitt provided an update about the support of Autodesk products on Window Vista. She states that AutoCAD 2008 and AutoCAD LT 2008 will be supported in both 32-bit and 64-bit versions of Vista.
But perhaps more importantly in the short term is that there will be in "the coming months" support for AutoCAD 2007 and AutoCAD LT 2007 on the Window Vista 32-bit version.
There has been no official word of future Vista support for Civil 3D yet.
Once again Heidi, thanks for the update.