Well a few things:
Zelda Wii is not the most awaited game of this gen. It might be the most talked about and discussed, but like FF, EVERY Zelda game is put under one of the most intense microscopes. I'd say, though, there have been other bigger titles, more mainstream ones, that have been more awaited than this one. Don't get me wrong, it'll be a big title (potentially bigger because of the Wii's situation for later this year), but not the biggest.
Next, it's hard to think that unless Nintendo announces N6 at this year's E3, that they will slow down. Just because it seems that Nintendo is out of games, doesn't mean they can't and won't announce anything knew. Remember we know of Pikmin 3, Project Sora, and Retro Studios project. Only one of these will release in 2010 along with Zelda. The others are either 2011 titles, or maybe on N6. Point being, Nintendo just won't take time off. They are always looking ahead, but they still have a large Wii base they need to support, and will support.
Although I do think we'll start seeing announcements of 8th gen consoles in late 2010/2011 and released in late 2011/2012, it's not simply going to kill this current one off. It is a little daunting that the 8th generation, though, is now upon us with the Nintendo 3DS announced. Guess things will start unraveling faster than people think, but I can see some of this thinking as Nintendo isn't sitting back and waiting.
