Multiple open positions at Ubisoft Quebec indicate the company is working on an MMORPG. Some of the listings specify Wii U, although it's unclear if the MMO is for Wii U, or if these are two separate projects.
The French publisher isn't usually known for MMO development, with Might and Magic Heroes Kingdoms one of the only massively online games from Ubisoft.
A tweet from Ubi communications specialist Emile Gauthier (via CVG) plugged the MMO job listings. Among them are a senior programmer for Wii U, network programmer for Wii U, and tools programmer for a AAA MMO.
This doesn't necessarily mean Ubisoft is working on an MMO for the Wii U, but the job listings seem to suggest it. Nintendo of America president Reggie Fils-Aime has previously said that online plans will rely on the publishers themselves, and Ubisoft has been an active supporter of the upcoming platform.