If Nintendo did that, I'd probably go exclusively Xbox 360, or even PS360. I might eventually get one, but I would probably wait for a price drop, and my hype would be extremely low for it compared to the Wii. Basically I would be pissed because I would feel ripped off by Nintendo, by promising so much potential in the Wii only to cut the life short early and release a new console.
Why should I get a Nintendo console if it just did all the same things the HD consoles did with no way of differentiating itself? The appeal of Wii to me is that it is so different than the other consoles.