One of the great new features of Windows 2008 Failover Clustering is the removal of the "same subnet" restriction. This is a huge feature for multi-site clusters as I personally know of several customers that did not implement a multi-site cluster specifically because of this limitation. Most of the folks that I spoke with at TechEd are excited about this new feature and are considering multi-site clusters specifically because of this change.
Anyway, at TechEd this year the SQL folks made it publicly known that SQL 2008 will NOT support clusters with nodes running on different subnets. Ouch! This is a mighty blow to anyone considering a stretched 2008 cluster as SQL is certainly one of the top cluster applications.
Personally, I'm dumbfounded by this and I don't understand how Microsoft allows a product to ship that doesn't support this feature in clusters. This issue was revealed to us at the MVP conference in March and my response was to obnoxiously shout at the SQL team, "Boooooooo, hissssssss!"
Hopefully, this will change quickly as more customers demand support for this feature in SQL.