If I was to guess I'd say they're going to attempt an all-in-one - a handheld system you can "dock" at home with the dock hooked up to the TV.
Walk in the front door - dock the handheld - pick up your traditional controller and off you go.
It ticks the home console box, it ticks the handheld box, it ticks the off tv play box (take it out of the dock and sit on the sofa).
That said - this being Nintendo it could be something completely out of the park - they can be a bit random can Nintendo!
I cant see how that would work, it wouldn't be powerful enough for a home console and handheld fans would just buy a new 3ds