Well your definition then of next gen is nothing more than a replacement of an existing model regardless of capabilities and specs
That's all they are...a console generation is not defined buy it gazillion pixel shaders or it's ability to suck up power at a stupid rate.
It's merely moving from one console cycle to another, Nintendo have just completed that Cycle.
Wii or even Wii U for that matter might not be considered next generation machines by all you graphics whores out there but in my eyes they were next generation in terms of controls.