Turns out Ubisoft developed Rayman Origins specifically for the Wii U, as they thought the console would launch earlier than currently planned.
“To be honest, we were on Wii U very early – even for Origins," said Rayman creator Michel Ancel to Nintendo Power (via Nintendo Everything).“… We did not know exactly when Nintendo would release the system, but we started making Origins for Wii U. [At that point], we thought Wii U would come out a lot earlier. We worked very closely with Nintendo [on Wii U] early on, giving them feedback on the various prototypes.“When we finished Origins, it was time to start thinking about Wii U again, because [the hardware] was nearly complete. So to answer your question, we wanted to make a Rayman game and started to explore how we could make it interesting using Wii U.”
Instead of Rayman Origins, we're now getting Rayman Legends for Wii U. The game was supposed to be parth of the launch line-up for the console, but recently slipped to early 2013.