That's basically what happened with Killer Instinct when it was supposed to come out for the Ultra 64. It was announced so early that you see how that ended up playing out. It was even a running ad at the beginning of the actual Arcade cabinets before the title of the game popped up.
Also, this is basically what happened with Beyond Good and Evil 2.
Microsoft and Sony both know that they have to do something big to try and steal as much of the spotlight as they can away from Nintendo or else that will be all anybody will be talking about at E3. Unveiling early plans for their next systems is the perfect way to do it. They don't have to show off any actual hardware, just simply show off mock ups of how the games will look and provide details on possible features. Similar to what Nintendo did last year basically.
Again, this has nothing to do with Nintendo. Why would Geoff make what amounts to a no duh announcement about what we already know regarding the Wii U being featured at E3 and them covering it? C'mon. "More details soon" implies that it's something we don't know anything about yet.