I'm surprised how many people are in the "they never lost me" department. When I was a kid I had a SNES. Then the new generation came along and I had no money to buy the n64 nor did my parents want to to buy one. So I grew out of the Nintendo stuff and nothing they did from the n64-era until now gave me an incentive to go back.
I figure it would take them a monumental amount of effort to get me back to them, and my list pretty much amounts to almost all of the stuff that the op listed.
For starters, they have been regurgitating the same franchises for the last decade, franchises that I couldn't care less about. So they would have to create new appealing IPs and revive franchises that I did care about back when I had my SNES (F-Zero, Star Fox).
I also don't care about the motion-gaming crap, so there needs to be a decent controller which is supported for all the games I would want to play.
There also needs to be a smooth and robust online infrastructure.
Decent 3rd-party support is a must, since I don't want to wait a whole year for anything to play while in the meantime the console collects dust.
Decent graphics.
So yea, they pretty much would need to do EVERYTHING different as opposed to what they are doing now. Of course, I don't expect them to succeed or even attempt all of this, and I don't mind since I have plenty of alternatives that fulfil my gaming needs (PC+PS3). So their core problem is that not only would they need to appeal to me, but they would have to that more than the competition already does and I highly doubt that Nintendo would think that this is a viable market strategy.
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