http://blogs.technet.com/filecab/archive/2007/07/24/new-in-windows-server-2008-breaking-the-5k-folder-barrier-in-domain-based-namespaces.aspx has the details of something I know a lot of organisations have been wanting for a long time.
Have an entry over at http://osusuki.spaces.live.com/blog/cns!DED344FDCB7C8F28!200.entry where I briefly have a look at some of the issues from MS07-039 and the previously released MS07-029.