There is none. The only info we have ever gotten for a date was "sometime in 2015"

http://www.technobuffalo.com/2014/10/30/nintendo-explains-why-the-new-3ds-wont-hit-america-or-europe-until-2015/

Nintendo made a comment about Monster Hunter and it's relevance to the New 3DS, so I suspect they will come out side by side in some kind of co-marketing campaign relatively soon. Monster Hunter is speculated to be out late March, if you trust a few online retailers saying so. Hoping for an early 2015 release along side Monster Hunter 4 Ultimate myself. I want that Silver Monster Hunter themed new 3ds!

@vrikk: Why not just buy the Wii version?

@oldenglishc: The print run of the Wii version was fairly low, what with it being a delayed port that Nintendo begrudgingly put out in North America (using the Euro localization, so everyone is British as fuck) and was only distributed through Gamestop. It's scarce enough that the prices for it run pretty high, depending on where you look.

@bisonhero: Seventy five bucks is still a lot cheaper than a than a new 3DS.

I want it for more than just Xenoblade, but it's still a nice enabler reason. The game itself will be cheaper than the Wii version, be "enhanced", and portable.

And again, new console. I could sell my 3DS XL to offset the price.