It has been my hope that the whole reason for opening the Maemo project to the public was to observe how people will use Maemo devices and deduce the main use cases from these observations. To me (personally) it seems to be a much better idea than mandating a bunch of use cases and forcing them onto potential users.

Reading books is certainly one of the main use cases, if you take into account that FBReader has been downloaded 13652 times from maemo.org alone. And yes, 4.1" is definitely better than 3.5" for reading books.

Again, while we do not know what display makes sense for watching movies, it seems to be a commonly held opinion that 4.1" is better for watching movies than 3.5".

The third use case I mentioned (web browsing) is officially the main use case for the current crop of internet tablets. As it also loses some experience quality from shrinking the display size, I can't help but wonder whether it is still among the main use cases for the upcoming device(s)?