Nintendo will continue supporting the 3DS, but with new IPs and maybe remakes ( Majora Mask 3D anyone?) since the 3DS already has Mario Kart, Smash Bros, Zelda, etc..

I am much more of a 3DS fan than a Wii U fan (don't have a Wii U and have two 3DS) and I find this a very skewed position. 

1. I don't think Nintendo thinks the 3DS is doing perfectly fine, in fact, they realize that it is their main source of income right now, but at this point there isn't much software the 3DS doesn't have that will make it sell more than it is.The question is that of software sales then. How can Nintendo maximize profits from software (which is their main focus anyway?) They can do that by releasing more of pokemon and more of smash. That is all they need from the 3DS, as a company looking to maximize profits. 

2. The Wii U is an entirely different issue. Nintendo knows their games have potential to sell well on the Wii U (as evidenced by Mario Kart 8) they just need to release enough of them to expand the hardware-base so that more people will buy the games after they own the console for game "X". This in turn will allow them to have another platform to gain profits from and consequently software. For this purpose, especially since it just started making profits on hardware and has been selling quite a bit of software, the Wii U is not dead. 

3. Nintendo is a very conservative company. They don't care about marketshare as much as they do profits (unlike Microsoft and Sony whom rely on brand identity for multimedia sales.) For this reason, Nintendo will forfeit 3DS marketshare in order to maximize profits from the sales of their games (which will sell a lot on 3DS whether the install base is 80 mil or 130 mil.) That is why they must focus on the Wii U. If the WIi U stopped selling at this second, it would be bad news for Nintendo profit-wise. If the 3DS only sells 80 million instead of 130 million, then they will live, assuming a successful (as in profitable) Wii U. 

Nintendo is simply incapable of suporting both systems at once. When they made tons of great 3DS games, Wii U got nothing. Now they're working on many great Wii U games, and 3DS isn't getting much at all.

Source? I dont think i ever heard this year they think 3DS is doing well, especially missing selling marks. They need to support both HH and Console, its not the fact they left 3DS and beside 3DS has games this year, its just many compare it to 2013. Compare this year and 2011 or 2012 in terms of releases

Edit:  2011 Major Releases (US)

2014 Major Releases (US)

Steam doesn't play anything like Advanced Wars, has a completely different setting and asthetic, and they never once said it is replacing Advanced Wars. (And project steam looks godawful)

I'm talking asthetically. I've seen a lot of footage of the game and many screenshots. It may be fun to play, but it looks so so ugly. It's seriously hard to watch.

New setting and theme, but it's turn combat strategy by the AW team. They did this instead of AW. Yes, it did replace AW on 3DS.

They need to send out a demo for the game. Its really..... different (i guess cuz of the artstyle), but if the game is good then a must buy! Hopefully people wont discredit it solely for graphics >_>

3DS ain't going anywhere anytime soon.