I've just been looking at the videos of BB on IGN, it looks pretty fun, I might actually buy it when it's released.
As for sales....it's a tough call, but I can see it hitting a million eventually.
http://uk.wii.ign.com/articles/871/871124p1.html <- M & B play with the level creator
Playing : PC AOE, DiRT 2, Runes of Magic, Wings of Prey & Planetside 2
Wii U : Nintendoland, Super Mario U & Fifa 2013 demo
DS : Guitar Hero : On Tour
Formerly unknown as Vengi