The Nintendo NX software development kits have already shipped and are being used by developers now, but the non-disclosure agreement has not yet lifted so developer’s lips are sealed. The new architecture is supposedly much easier to develop for, with some WiiU game ports already rumored for the new platform – such as ‘Splatoon’ and ‘Legend of Zelda’. It’s highly speculated that the NX architecture will be x86 like Sony’s Playstation 4 and Microsoft’s Xbox One, which run a custom AMD accelerated processing unit that combines Radeon graphics and AMD jaguar cores on a single die.
There are rumours regarding the power of the CPU in the Nintendo NX say that it may be 15-30% faster than the PS4, this is yet unconfirmed as Nintendo have, in recent years, shown a liking towards underpowered chipsets that take advantage of Nintendo’s titles with their comparatively primitive cel-shaded graphics style. One rumor suggests that ‘the NX will be more than the PS4 by a noticeable amount‘. Take this with a pinch of salt though, whether or not it’s more powerful could signal a change in perspective from Nintendo, where historically consoles have lagged behind as far as technical specifications are confirmed.
Reddit user ‘stimpak_vendor’ claims to be a AAA developer who works the NX devkit and developing a game for about six months, claims that the devkit likely isn’t backwards compatible and that the controller is like a game system on it’s own.
Sources:  http://www.neogaf.com/forum/showpost.php?p=200827598&postcount=5735