Actually we have an established 7 person SAN team. And just last week, I had to work with them for many days laying out and establishing a new multi-cluster system. DBA's don't need to be able to administer the SAN, but we do need to understand I/O. And this means being able to talk the talk with the SAN team. As SAN's replace internal RAID arrays, it will be more important to at least know what a LUN is and how your disks are configured in the SAN, regardless if you know how to administer the SAN itself.