I'm just passing along some information that has been making the rounds (I found it on Guy Burstein's blog).
If you attempt to install SQL Server 2008 on a machine that has Visual Studio 2008 installed, it will fail. The requirement is to have VS 2008 SP1 installed, an update that is still about a week away from release. And you need the 'real' SP1. The same problem exists with the beta for SP1.
So, for you developer/database people out there, it looks like at least a week of waiting to get the combination on a single machine.