Hi Cort. HAL recently opened its bookings for Bermuda 2010, so I doubt Celebrity will lag too far behind. I suspect they may have to work out some final details.
I've been to Bermuda four times, and loved them all. It's very easy to get around on your own, as they have an excellent bus and ferry system. There is also a lot to see and do. Even after four visits, there's more on our list.
I was on one of Summit's sister ships, Infinity, and she had a great layout and nice public rooms. As Cruise Fanatic says, the ship's size won't allow her to fit into St. George's Harbor, but you can always visit the town by bus and ferry from wherever you dock.