first party support will probably be bigger on wii U, third on 3ds(japanese).
they said theywill make wii u games until the users get satisfyed.
if you like mario kart, 2d or 3d mario, smash bros, donkey kong, the wii u version of these games is far superior.

i would get a wii U.
3DS sucessor is coming sooner than wii U sucessor, and is almost certain that 3DS sucessor will get backwards compatibility. Wii U sucessor may not get.
So, get the wii U and wait for the 3DS sucessor.

I'd say 3DS now, Wii U near the end of its life.

The 3DS will offer you far more games at this point in time and for a cheaper price too. 

Bayonetta 2 comes with 2 games for the price of 1, you get Xenoblade Chronicles X on Wii U, plus Zelda U, Star Fox U and whole bunch of others. instead of getting the normal or new 3DS you could always get a 2DS. They're only 99 bucks. Which is not bad at all. Fire Emblem and Bravely Default (Also the upcoming Fire Emblem If and Bravely Second, plus a lot of others) are on the 3DS, however I believe they are working on a home console Fire Emblem. (There is also to consider the Shin Megami Tensei X Fire Emblem crossover, which will most likely play like Fire Emblem). Personally I would go with the Wii U. Especially since it is backwards compatible. 3DS has a ton of nice games but you can get a 3DS or 2DS for a very cheap price. Once Xenoblade Chronicles 3D releases, the price of the Wii version will go down so then you could buy that for your Wii U.

NOW, as for the next home console, Nintendo always gives 5 years MINNIMUM lifetime for every console. Which means we won't be seeing a new home console till the end of 2017 or beginning of 2018. So it is definitely safe to get one.

I hope I helped!! :D

3DS has more quality games, but you'll probably just end up getting a Wii U because it's a console and it will have Zelda and XCX.

Wii U by a huge margin for the local multiplayer alone. Super Mario 3D World seems ideal for that age, but games like Mario Kart 8 and Nintendo Land should also be fine.

I have both the Wii U and 3DS. 

Your pros are quite good for both systems. I don't think there is too much to worry about with support for the Wii U after this year, but that's a toss of a coin for any system really, but it does already have a very good library. I am going to point out that it isn't a Wii emulator. It is a duel boot system, kind of like with your PC running windows and Linux. Although instead of a boot loader to choose your OS you can switch to either on the fly from within each OS. But yes, it can run any Wii game so that exponentially increases the library for the system. It's quite similar with the 3DS being backwards compatible with the DS though. 

For the kids, certainly the Wii U, no contest. 

The gamepad can be used within roughly 25-30 feet of your console as long as there isn't too much interference. 

I myself was worried about Bayo being anti God, but I really didn't find it to be. Despite many of the enemies being called angels that's about where it ends and the story doesn't have that much to do with either or anyway. 

Personally in your position I would likely go for a Wii U, but I play mine far more than my 3DS. There are lots of good classic rpg's available on both the Wii U and Wii virtual consoles. 

You don't dig the new 3D? :O

Hey guys, thanks for all the replies, this was awesome! Sounds like I'll probably go with a Wii U, now I just need to see if I can find one cheap or save some money. Sounds like Bayonetta would be good for me too.

Thanks again!

Just gonna say Wii U
You can buy refurbished ones from Nintendo's website for 200$, so I would go with that
Better value for the same price

Wii U does have a severe lack of RPGs though, so be warned

I saw one of those in the past, but it doesn't look like they have any right now.  I'll have to keep my eyes open for them.