iSCSI is definitely neat. I'm thinking of lots of different ways to use it already. If I actually want to use OpenFiler though I'm going to need to invest in some new storage and start fresh with LVM. Geeks.com still has those $50 500GB drivers so I'm thinking:
6x500GB in RAID5 = 2.5TB (maybe a hot spare too)
And I can setup the existing drives in RAID mirrors.
250GB for audio
300GB RAID stripe for Logic -- although I don't know if iSCSI is going to increase disk IO latency too much. Need to research that.
Plus whatever other left overs I have for TimeMachine backups, document backups, etc.