It will premiere on January 15th on Disney Junior, but they made the episode available now on iTunes for free (only this time). It can also be watched on this site:
http://watchdisneyjunior.go.com/the-...-rise-of-makuu

Sadly, that's only in the U.S. so I haven't seen it yet myself. *avoids reading spoilers in s-tlk's post* ><