He's getting a lot of heat all of a sudden, but I have AceBandage's back on this one. Wii worked for them, there's no doubt about it. But even with that success, I agree that it would be in their best interest to brand their new console something else assuming the rumors that they're serious about courting the "hardcore" gamer and getting a piece of the multiplatform pie are true. This is working under the thinking that Nintendo now feels confident in their ability to pick up the nongamer (as they've already done that with two completely new brands), and is setting their sights on drawing from the people that right now prefer PS3 or Xbox. The people that dismissed Wii from day one because they thought the name sounded dumb, or that were maybe interested but left it behind because it didn't snag many AAA third-party games. The dudebro crowd, if I want to use a quick and imprecise abbreviation for it.
The DS to 3DS transition is a different beast, I don't like that comparison. The DS was THE main handheld platform for consumers and developers alike (aside from, most notably, some Square Enix stuff and Monster Hunter). It hasn't had the same problem with picking up serious third-party support like the Wii has, and I don't think that those with the entrenched and anti-casual mindset dismissed DS like they did Wii. To these people, Wii is synonymous with casuals, and that's not the sort of thing that they want to be immediately associated with.
It's bullshit reasoning. But it's reasoning that is being used, and right now it's one of the factors keeping Nintendo away from *cough* complete global saturation.