I am currently waiting to take delivery of a new Canon 20D whenever the boat to the UK arrives. I have just sold all my old olympus underwater gear on Ebay, so I have to wait until someone releases a housing for the 20D.
However, one thing that I feel would really help underwater photography is a housing that can take a DSLR and a battery grip. The weak point in a housing is the seal. With advancements in memory cards, I could now stick a 4GB compact flash card into the camera and be set up for the week (as long as I didn't want to change lenses). But the single battery certainly won't last that long, hence the usefullness of the grip.
So come on Ike make that housing a little bit bigger and let us take more pictures. I am sure someone can design a housing that can take the camera with or without the grip.
Cheers
Gary