New Super Mario Bros. U Blind Walkthrough Part 30: Ghost Leg Lottery

... is the name of that cloud-walking segment when you change paths at every junction. I couldn't think of the name in the video though, which is why I put it here.
http://en.wikipedia.org/wiki/Ghost_Leg

-Time Stamps-
0:00 Item Box Win
0:46 The Two Fuzzy Mini Stages (They're unmarked)
2:34 Meringue Clouds-4 - Bouncy Cloud Boomerangs
10:08 Meringue Clouds-5 - A Quick Dip in the Sky (The name reminds me of Pegasi! o_O)

Enjoy!