It depends on what you mean by mainstream audience. If you're talking about kids and families, then sure, but like I said I think that demographic is much more likely to pick up the console during the holidays regardless of what Nintendo puts out in March. Nintendo, by their own admission, does the majority of their business during the holidays and that's due in no small part to the fact that this is when families are willing to make these kinds of purchases.
If you're talking about about teens or adults who are multi-platform gamers, then I'm not really seeing the argument that a new HD open world Zelda game isn't a huge draw. If they deliver on the promise of a great, open world Zelda game, that's going to be a big deal in the larger gaming world, especially in March when we don't typically see a lot of big releases.