Oracle on a SAN is a great thing as long as you follow basic I/O tuning rules. Don't let your EMC guys tell you RAID level doesn't matter; it does. Don't let them tell you everything can go on one filesystem; it can't. When your host is connected to the SAN, you will probably see performance imporovements over SCSI devices because the throughput of Fibre Channel is much better than most (if not all) SCSI.