The Wii U will be able to provide a home for free-to-play games, as Nintendo president Satoru Iwata revealed in the company's E3 2012 analyst Q&A session (via GamesRadar). The console apparently features an elaborate enough Digital Rights Management system to support developers interested in "additional e-commerce options" like "free to play and microtransactions."
Asked if the support for free-to-play can be seen as a sign that Nintendo might soon tread in that direction with a first-party game, Iwata stated pretty clearly that it's not something the company is considering right now. "Currently, we are not actively looking at free to play for our first-party content and I don’t think that’s a direction that we should go in right now," he said, though he later admits that there is "no intention to deny every possibility of free-to-play."
There's a lot of ground covered in the seven-page Q&A, with Iwata addressing many of the questions that industry observers have been asking in the wake of E3. If you're curious at all about the Wii U and Nintendo's bigger picture plans for it, the Q&A is definitely worth a closer look.