Stages are a mixed bag but there's some really awesome stuff there. Miiverse is integrated REALLY well in its stage, very creative way to keep it "appropriate" but still allow community contributions. I really like the premise of Wrecking Crew, though I'll have to play it before making a judgement call. And Jungle Hijinxs is AWESOME. Not at all the DKCR gimmick I expected, but it should definitely make for some dynamic games.
Some weird choices for returning stages (Norfair? Port Town? 75m!?), but overall I'm happy with it. And the assumed ~5 stages that are still hidden, which I'm sure there are.