Unfortunately and surprisingly, that's not the solution. Look at the 3DS, it has AMAZING GAMES and Third Party Support (POKéMON X, Legend of Zelda: A Link between Worlds and Ocarica of Time, Fire Emblem: Awakening, Resident Evil: Revelations, Bravely Default, Street Fighter 4, Super Mario 3D Land, New Super Mario Bros. 2, Animal Crossing: New Leaf, Shin Megami Tensai IV, Zero Escape: Virtues Last Reward, Luigi's Mansion: Dark Moon, (need I say more?), and sales are still declining.

It's not just a Nintendo thing, main stream video game consoles and Handheld's are struggling as a whole. Article here:

http://www.cnet.com/news/video-game-software-sales-continue-to-slide-in-august-on-lack-of-new-releases/

Despite success of PS4 and XBone, the console sales are still significantly lower than last gen.

The 3DS honestly has been selling poorly in North America for about a year and a half now, even last year when it had some great games (Animal Crossing, Luigi's Mansion 2, Fire Emblem, Pokemon X/Y, Zelda: ALBW) it wasn't selling great per se, it was just kinda not noticed because everyone was fixated on the more spectacular failure of the Wii U. 

But the 3DS has been performing way below the GBA in North America (not going to even compare it with the DS) for some time.

Nothing. The 3DS has been out too long and needs to be replaced. Nintendo should release new handhelds every 3-4 years with the way the current market is going. The WiiU, well, it's failures have been discussed to death already.

Yeah, I get that they probably are leaning towards a Fusion platform driven largely by a portable of some type (most likely) ... but I have to wonder if waiting until 2016 even may be too long of a wait. 

They're taking a lot of damage and losing a lot of brand relevance in the meantime. 

I think because of the New 3DS......Nintendo wants at least 2 more years for the 3DS.

I think they're putting it on the New 3DS Model, and Amibos, that and their new upcoming games.

I get the New 3DS from the POV of Japan, especially where Monster Hunter is very popular and the second stick revision makes some sense ... but from North America ... I dunno. If people aren't buying the system anymore, I don't know if a second analog nub + a faster web browser on a screen that's lower resolution than even $99 tablet is going to be all that appealling. And yeah, Xenoblade, but a port of a 4 year old Wii JRPG not named Final Fantasy probably isn't lighting the US on fire either. 

Clearly they were hoping the 2DS would cause a big uptick in sales too, but that hasn't taken either. 

That's what happens when you announce a new version to your system.

The new 3ds was announced in the last week of august. It wouldn't have that much effect in one week, and most people (not forum goers) would probably not have heard of it yet.

Nothign can be done. Everything's over.