I don't think the donations idea should be ruled out on principle, but if it's too hard to implement practically I wouldn't be too sorry to see it go. I think that what I mainly want is for there to be a single user interface that shows free apps alongside proprietary ones on an equal basis.

The Maemo Select pages do a pretty good job of that, but it's not entirely clear (to me, at least) whether the Ovi store will work on a similar basis, and it should.