Well, I don't think the software lineup, battery life, or price point, are going to be the main hurdles for the 3DS to outsell it's predeccesor(which actually makes me laugh my ass off since the thought hadn't crossed my mind). I think it's going to be the ability for gamers to see the relevancy of 3D in the gaming medium.
And that will have most to do with marketing. You can market 3d, just not the traditional way. It can't be a top-down approach where a commercial or ad shows you how cool 3d is...because tvs and 2d banners can't do that. It's going to have to be bottom-up, which can be the absolute best marketing in this case, or the worst. Nintendo fans are going to be open to buying the device and so their will be an initial consumer base. When people who are unsure of buying the device want to consider the purchase, the marketing will come face to face from their friends who already own it. It HAS to be that way, it's the only way they'll make that mental decision that 3d has relevancy in the gaming medium. Friends and family telling you or showing you something is good is way more psychologically convincing than a businessman telling you the same thing (in this case the "business man" can't even show you).
The downside I think is that if 3d truly does not enhance the gameplay mechanics (not doubting it will please the eyes) then consumers are going to know that right away from the bottom-top approach when they see it doesn't work in person. They will then have 100% proof, to them, that the purchase isn't necessary. Traditional marketing through ads still actually leaves the consumer in the air about the actual functionality of said product, which although most think that is bad for sales, now you can see why it may be a good thing.
I personally am in the same position as everyone else, despite having seen the ads and hype reels. Does 3d make a difference?
