Provideocoalition has a review by Allan Tépper, of the Promise Pegasus Thunderbolt RAID 5, which combines high performance with data redundancy for HD film editing. If you don’t know anything about RAID’s read the wikipedia entry for a good heads up.
The review turns out favourably for the incredible speed (even using a mac mini or a macbook air) and the decent redundancy (If one of the 5 drives corrupts, the other 4 can reconstitute it when you hot swap in another drive). Allan also has a good article on setting up an edit suite with a Pegasus RAID, Mac Mini and daisy chained displays.
UPDATE: Ken Stone has an incredibly thorough review and walk through on how to set up your Pegasus Thunderbolt Raid. If you’re thinking of getting one, read this first.