5-10 M range (and i know that's a pretty big range). the large userbase won't really help this title 'cause the blue ocean user base (like my mom) won't buy zelda. it should sell on par with mario galaxy and ssbb as that is the size "core" audience on the wii. sales could be adversely affected either by the game being too much the same or too different...no matter what you do chances are you're going to piss someone off.
as a long time zelda fan...i'm probably not going to get this one if it is too much the same.