As far as worrying about what a reviewer is gonna score the game, I don't pay attention to that stuff anymore. Review scores are all BS anyways. If you are going to listen to somebody you don't even know for advice on which games you will like at least ignore the score and just read the review.
Anyways, I have to agree that considering how little effort Nintendo has put into hyping the game so far its pretty impressive how much hype there already is. With that in mind, if/when they do start to hype the game it could get out of hand. So if the question is can it live up to the current hype? Well then I think most certainly. But I don't know what Nintendo has planned so I don't know about future hype.
What I can tell you is that casual gamers who practically never play video games are interested in the game. My example is anecdotal, and thus admittedly non-conclusive, but when my mom calls me specifically to ask "When is that new Space Mario Game coming out?" well that surprises me. For a bit of background info I did show her the videos from E3 if I remember correctly, back in mid-late July.
Now the reason this is interesting is because a 2 minute video impressing on someone who is less than a "casual gamer" enough for them to not only remember it but be interested enough to ask some 2+ months later is quite impressive. And while I won't be able to show the video to every casual gamer I think a similar effect can be generated by a well targeted ad campaign that taps into the nostalgia of Mario. And I don't see why Nintendo wouldn't do a nostalgia based ad campaign for Mario as it really is associated with fond memories for millions of people and a lot of those people don't play many (or any) games anymore.