I don't think a Wii2 is any sign of compitulation on Nintendo's part. A five year lifespan was always in the cards for Wii from day one.
That is why Nintendo went without HD. Five years ago it wasn't relevant enough but Nintendo knew in five years time it would be but by then they'd have another console out.
Unlike MS and Sony which both experienced immense losses on their consoles at first this gen, Nintendo profitted off the Wii from day one. MS and Sony are both making money now, but if either one suddenly jumps into the next gen (with another loss leader) then this entire generation, and in fact, their entire video game histories will be for naught because they will have both lost more than they earned. Both MS & Sony need to milk the current systems for everything their worth for as long as possible.
Nintendo on the other hand can move ahead, as planned all along, without that consideration, and in fact benefit from being the new 'it' thing for a couple years before 720/PS4 come along.
Also, Nintendo always says they'll bring out a new system once they're out of ideas for Wii. Well, every major franchise has now been out on Wii, many twice (3d Mario, Metroid, Kirby and Zelda will have their seconds out soon). Yes, I know, Star Fox and F-zero.... I'm guessing we'll see Star Fox Wii this holiday season (much like Zelda OoT 3DS heralds Zelda:SS so might StarFox 64 3DS. F-zero has not had impressive sales, and would make a better 3DS than Wii game anyway. Pikmin is already promised to Wii too but again, not a big seller.
Normally I'd be concerned about the daught before the storm of a new system, but Nintendo has so many games already announced or released in Japan to bring over that they'd have no problem filling the next year with worthwhile games.
For myself, my last console was a Colecovision, and honestly, I doubt I'll upgrade to any system. I'll probably just be playing Wii games for the next 10 -20 years. Fortunately Nintendo makes a lot of games with endless replay value. But I'll miss the Wii support once a new system comes out all the same. It's always nice to have something new to look forward to.