I'm pretty sure that a proper 3D Mario/Zelda U/Metroid announcement altogether can pull some units with the core gamers. In fact, part of the early Wii success was because this. We already know about MK and SSB, and adding those 3 announcements will make some people buy it.
And 10M is, right now, almost an impossible number for 3DWorld.
For the second part, I agree. NSMBU can have the best gameplay, but it is too similar to NSMBWii.
They said Zelda will probably be shown on the 2014 E3, and a 3D mario already released... Yeah Super Mario 3D World kinda counts as one. At this point the only thing they could announce would be a Metroid game, and if it's anything like Metroid Other M then they better not show anything at all. At this point I think they only have Mario Kart 8 and Smash for 2014. I doubt they will announce anything else for 2014
True I think that it will sell even worse than Super Mario Sunshine. Such a shame, I finished the game yesterday, and it's truly awesome!
"I've Underestimated the Horse Power from Mario Kart 8, I'll Never Doubt the WiiU's Engine Again"