I honestly never knew this was up for debate or that people was confused on what Next-Generation meant. I guess some people don't consider WiiU Next-Generation, i don't know. Anyways with the recent thread asking what makes it next gen made by Mazty I'm going to go ahead and clear that up for you. I also want to point out 7th generation just signifies how many gens games has been through since it has began while technically some consoles are only going on their 3rd generation like xbox. XBOX entered the 6th generation of games but it was in it's first generation. They are two different things and does not signify power or innovation. We are going into the 8th generation of games, not the 8th generation of a specific company's console.
Next generation is simply the next step in technology for that company. For example PS1 to PS2, XBOX to X360, PSP to PSV, and now Wii to WiiU.
Xbrawl also made this comment which will help further explain this subject.
This is true, and it was the same thing when the Wii launched. Nintendo could release something that was only marginally more powerful than the Wii, and if they intended to go head to head with the next Xbox and Play Station, it would still be next gen. It's their offering to the next generation of consoles. It doesn't matter how damned powerful the console is. What if the Nextbox is 2x as powerful as the WiiU, and the PS4 is 2x as powerful as the Nextbox. Are they all in 3 different generations? Then how do we categorize them?
In short: A console's generation is determined solely on which consoles it is in primary competition with.
Gen3: NES, Master System, Atari 7800
Gen4: SNES, Genesis
Gen5: N64, Saturn, PS1
Gen6: GCN, Xbox, PS2
Gen7: Wii, X360, PS3
Gen8: WiiU, X720, PS4
So yes WiiU is next generation. Power and innovation has nothing to do with it. Now let's read a definition of what Next-Generation means.
Next-Generation pertaining to the next generation in a family; also, pertaining to the next stage of
development or version of a product, service, or technology