It's a little bit complicated to use... like you have to scroll all the way up again if you find that the file you're looking for is not in the currently selected directory, but in one of its sub-folders. a good chooser would let you select directories from an additinal tree on the left. (there's a very good reson why file choosers normally have two or even more lists to select directories, files, recently used... blabla). in this case obviously form didn't follow function, but was dictated other factors.

anyway, the point wasn't that it's less comfortable than what we have today, the point is that it would run on an N800 an therefore (according to the announcments about Maemo5 not being ported to N8x0 because of it's clutter-based, 3D-accelerated interface) probably isn't the real thing.