Just saw an ad for this in Post magazine, and I guess they showed it off at NAB this year. The new JMR Lightning Quad Tower for Mac Pro is a PCIE expansion tower via thunberbolt for the new MacPro, that includes four full sized PCIE expansion slots, a built in RAID controler wth 9.6TG capacity, and brings your USB, Ethernet and Audio ports to the front.
Very cool. I am sure it is not going to be cheap, but what a great idea! Make a real MacPro out of a new one, if only Thunderbolt was a little faster.