Terrablock is the SAN system that Root6 are starting to ship in numbers - I put one in at Teacher's TV last November and it is a superb solution for low-end video facilities. It starts at 3Gbytes and scales - with small numbers of clients it even supports hi-def video. It talks over 2gig fibre and appears to the client OS as a SCSI device but it has a management layer (that you can access over the network) that allows you to create and re-size volumes. At a fraction of the price of similar video-type SANs we think it has a great future - Chopper has a written a PDF you can read here.