Thursday was a busy day at Microsoft. RC1 for Longhorn is now out and available for download. To read up on some analysis about the update, check out James O'Neill's post.
Going over to the other side of the "pond," Keith Combs mentions some good news around virtual machine VHDs for Exchange SP1, SQL 2008 Nov CTP, and System Center & Forefront. Go download these pre-canned installations to test before your deploy.
Also, Keith details a really interesting tool called Service Pack Blocker Toolkit...not sure what that's all about 🙂