The one thing that really appeals to me about this game, and the videos I've seen of 3D land, is that they both seem to be a real distillation of 2D mario in 3D, all the way down to the flagpoles at the ends of the stages.
It's very abstract, very "point A to point B." I could learn to love that.
I mean, if you're going to take mario in a "back to basics" direction, then you might as well go all the way, and just make as pure a platformer as possible.
Single player videos like the one in the OP have definitely calmed my nerves considerably over the last few days regarding this game. When there are 4 people hopping around, it's so distracting that it's hard to appreciate the finer points of the level design. I'm still not 100% hyped, but I'm moving in that direction. I want to see more of the game, to get a sense of the variety, and I need to know how big it is. Also I need to make sure they haven't sacrificed the single player experience to make multi easier... I don't think they have, based on videos like the one in the OP, and there was even a quote from the director to reassure people about this, but some of the impressions of people who played it at Best-Buy and E3 are still worrisome.
Also I think Nintendo did a terrible job showing this game for the first time. The initial trailer emphasizes all the wrong things about it. If the game has the kind of exciting platforming shown in some of the 3D Land videos people are posting, the trailer should make that clear. Galaxy's first trailer did a much better job selling the idea behind the game and showing the potential.