since the release of SQL server 2008 a common question has been...
"When will MS CRM 4.0 support this new wonder child" (might phrased differently)...
but now it's here... The support for SQL Server 2008 has arrived!
All you need to do when installing a new CRM server is to hit the update installation files, and you will have full support.
A couple of support hotfixes has been released as well:http://support.microsoft.com/kb/952601
Now go and enjoy 🙂