But now you're into a discussion of what makes a game system "next generation":

Is it a new way for the user to interact with the system; a controller with more buttons, an analog stick, Eyetoy, motion sensors, etc...?

Is it a large enough increase in graphical horsepower that the game can be presented in a new manner; Mode 7 graphics on the SNES, a move to 3D graphics, 3D graphics with the ability to add a lot of realism to the graphics or show a lot of seperate independent entities on the screen at once, etc...?

Is it a new way that the system interacts with the user; stereo sound, surround sound, a rumble pack, etc...?