I don't know, the whole "announce at E3, release in Fall" rumors have been flying around for a while, and just seem to be based on nothing but, "because of course they will". It's a given that they'll be talking about NX sometime this year, so why not throw E3 and Fall out there? They've the obvious "big" go-to times.
Oh yeah, because it's Nintendo, and they love to throw curve balls just because they can. So....yeah, salt.
The point has also been made that if there are any third parties out there with NX dev kits, Nintendo is doing a remarkably good job of convincing them to keep their mouths shut. But again, it's Nintendo, ninja stealth development is kind of their thing.
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