There's no way Nintendo would be stupid enough to put HD DVD in the Wii 2. I honestly can't believe anyone would even recommend it. It's not a fading format - it's dead. I'm sure every factory that was even producing HD DVD discs has already been converted to something else. They don't make the lasers anymore, they don't make the hardware, they don't make the media. It's dead. Let it go.
Damn it, I just checked out Wikipedia and read about CBHD - China Blu High-definition Disc, which are actually HD DVD (discs). Still though, they hold 15-30GB, so that would still leave Nintendo behind the competition...they should just go with Blu Ray. Sony Computer Entertainment of America (and Europe, Japan, etc) are in competition with Nintendo, Sony Corporation itself, is not, and they are only 1 of 19 companies on the board of directors, many of which are "friendly" with Nintendo, like Panasonic, Sharp, and Samsung and LG (I could be wrong, but I think LG makes the DVD-ROM for the Wii).