Making a WiiHD is counterproductive for Nintendo. If they make such a system, who would buy it? The gamers they are missing have chosen the PS3 or 360 over the Wii; if Nintendo makes a WiiHD, then third parties will use it as a third system to port their games to, so we end up with the same games on three platforms, and any gamers who have a PS3 or 360 will just ignore it since they have those games on a system they already have.
If Nintendo is going to make a new console, it has to be something that will convince gamers and third parties to say "screw the PS3/360, I'm going with Nintendo".
Veder Juda is hand crafted from EPIC FAIL, and is a 96% certified Looney; the other 4% is a work in progress.