Nintendo said in their statement that it would be a "dedicated gaming system". Weather it's a home console that can be portable or vice versa is another thing completely.
They did say all future "mobile" games the company will be making (all new games according to what they said no ports) will be compatable with the 3ds, wiiu, pc's, phones and the NX.. That could mean the NX will be both home and portable or it could mean nothing at all.
They could do the whole "Take the gamepad with you" idea and have a powerful home console and the GamePad/Controller be detachable and able to use 3ds/other game carts.
Though if they do that I wonder if they will be ditching the whole clam shell idea?? or 3d for that matter.
Regardless until e3 next year or the year after I don't see them saying much more about it.
I do however see them releasing the spec's for it where they didn't the wiiu just so they can say, "hey this is how powerfull the NX is, sony and micro aren't this powerful!"