EA and BioWare really want folks to buy Mass Effect 3 on Wii U, and to sweeten to deal, they're throwing in some paid DLC for free and the Extended Cut stuff. Two separate add-ons that garnered plenty of controversy for different reasons.
The first, From Ashes, introduces the Prothean party member "Javik" and a number of extra missions associated with him -- not to mention a good helping of Mass Effect lore and revelations (seriously, take the guy to Thessia). Javik was previously available only through Collector's Edition or as paid post-launch DLC for $10.
The latter, Extended Cut, is basically a more in-depth version of the original ending. This bit of content was released for free a few months after Mass Effect 3 came out, in response to some impressive community rage ignited by the game's controversial ending.
BioWare previously teased bonus DLC for the Wii U version of Mass Effect 3, though it was Nintendo who dropped the actual details.