Nintendo already learned that is not wise to lauch the most powerfull console (N64), so in that sense i think that the Wii 2 will be equal or little better then X360/PS3, with less expensive game development, less console/games price tag and with some suprises (like the D-pad on NES, shoulder buttons on SNES, analog stick and rumble pack on N64, the sensitive shoulder buttons on gamecube and the wii remote, nunchuck, balance board on Wii). And this suprises are what is going to lead people to buy Wii 2. It's a fact that in terms of power people choose a Playstation or Xbox, and if Nintendo cant battle in that way, they have to do something new in terms of gameplay that none of the competition have it (like the wii remote).
Now about that new kind of gameplay i have to say that in my opinion the vitality sensor is the prime candidate. I think Nintendo is not going to launch the vitality sensor on wii, and it's going to better it and put it on the new wii remote 2 (without that thing on the finger like that sensors of cycling bikes that exist's today on gym's).
About the price i expect the PS4/X360 tag along about 500 dollars/euros and the Wii 2 about 300 dollars (the most expensive Nintendo console so far was the NES, on today standards when it launched the price was about 300 dollars, so i expect something like that).
