What could the NX be?

[Toxy]

There is speculation about the NX being a new Nintendo console releasing in 2016 or 2017. 
On the other side of the spectrum, some have even speculated that it may not even be a home console, it may in fact be a Handheld.
I would be doing an injustice if I did not mention the Fusion platform theory as being speculation also.

Any speculation on whether it is the Quality of Life platform is redundant. Nintendo has stated that it the NX is dedicated to gaming. 

Moving on... what if (now this is a very big IF), what if the NX is something more in line with the Expansion Pack for the Nintendo 64? It is something to boost the Wii U's RAM or something to that effect to garner some more interest until they are satisfied with what the Wii U can offer and then they announce a new gaming platform.

I am probably wrong, but I do not think this theory has been addressed yet and if it has, I apologise. I could not find any theories on this.