The way these things are developing I can see the medium format firms going out of business in a few year's time.
Yes, I know there are differences, but would you choose a Hasselblad over a Canon 1DSiii or whatever 35mp beast they launch in a couple of year's time?
If I could afford it I would, most MF lense box outresolve 35mm any day of the week, even Nikon and Canons pro spec glass isn't as good. After reading FM canon have a real problem on their hands the 1ds II out resolved a lot of canons L glass and now the new 22mp version will probably be too good for what's left, Canon are going to have to spend some serious money sorting out the glass before they can realistically go any bigger.
People are always going to want huge files, 35mm will never get to the size and quality that a MF back will produce, just like in film days, bigger negitive, better quality.
I think a lot of the top guns at IS will probably go MF sooner or later, if they haven't already.