Ok, so not exactly a killer feature, but I know a few customers who have been asking for this for a while especially as most of the builds are engineered and deployed via SMS.  I think this is one of those 'nice to have' features. From Beta 2 BOL: "For an unattended installation of a failover cluster, you must use /qn.  The /qn switch specifies a silent installation, displaying no user interface dialog boxes, even in cases of Setup errors or failure. If the /qn switch is used, all Setup messages are written to Setup log files". You'll also be pleased to hear that we will now support mount points on a Windows Server 2003 Enterprise Edition cluster running SQL Server 2005.  This should be really beneficial to those who have a requirement to exceed the 26 drive letter limitation (great news for consolidation.