That looks like a nice alternative to an Xserve Rack.
I've been pondering and pricing Raid Setups lately and that looks great.

I also found this one
http://eshop.macsales.com/shop/firew.../EliteAL/RAID/

160gb Raid starting at $240, Firewire 800.
Has anyone tested playback with a Firewire 800 drive?

I'm thinking about the 320gb drive, as I only have about 70g of my content, and usually have no more than 6gb of custom per show anyway.