Nintendo of America president Reggie Fils-Aime has been quoted as saying that simply upgrading to HD is "not the way we at Nintendo do things. The way we at Nintendo do things is, you know, when we will move to a new generation, it's because there are some fundamental things the [current] console cannot do." *
Sorry, but what?
clockwise from top:
NES Versions 1 (Most popular), Famicom (Japanese version),
and Model 2 (bottom)
SNES Versions 1 and 2
The infinite gameboy, gameboy micro, gameboy pocket, gameboy advance, advance sp, ds, ds lite iterations...
Now, fine, the Nintendo Virtualboy didn't have a second version, the N64 and Gamecube both didn't have second models either.. though both did have recoloured editions to try to repackage the same product. But those machines were unmitigated failures. Whenever Nintendo has a successful product, they milk that product as much as possible, by releasing a new version right before the death of the previous version. So when the Wii is on its last legs, expect to see the Nintendo Wii HD out 6 months before Nintendo releases their next level non backwards compatible killer console.
It's how Nintendo has been shown to do business, even if their representatives claim otherwise.
Unless you want to make the claim that the Nintendo Wii is just a repackaged Gamecube with motion sensing. I can see your argument even if I disagree with it.