I'm obviously not the target market here but I would have expected something from Lego that's more builder focused. These don't look like sets that would take very long to build at all. So this is more like a playset, which is fine in itself, but then why team up with Lego?
Mario actually doesn't seem like the ideal Nintendo property to become Lego since you don't really associate Mario with vehicles or locales, which usually make the best Lego sets. A Star Fox Arwing, F-Zero vehicles, Samus' ship - those would make great Lego sets. The problem is that I just listed off lower tier Nintendo franchises that fans like us love, but lack the name value of Mario, Zelda or Pokemon. With Zelda you could probably create sets similar to Castle Lego since it has lots of locales. You could make sets based on the Temple of Time, Hyrule Castle, Lost Woods, Karkariko Village, etc.
Now Super Mario RPG would work really well with Lego. And those sets would be bought by me and other geeks pushing middle age and no one else.