Nintendo won't charge money to play games online on the Wii U, but it will probably charge you for other services.
Recent comments made by Nintendo president Satoru Iwata suggest that the company is looking to offer the same kind of tiered online structure that Sony currently has with the PS3.
On the Sony console, players can access everything they need to - online games, downloadable demos and content, etc - without paying anything. But those have extra disposable income pay a monthly fee to gain access to features that are above and beyond the basic online service.
Specifically, what Iwata said in an MCV interview was, "We cannot promise here that Nintendo will always provide you with online services free of charge no matter how deep the experiences are that it may provide, but at least we are not thinking of asking our consumers to pay money to just casually get access to our ordinary online services."
A lot is riding on the Wii U, and perhaps what the big make-or-break component will be is whether or not Nintendo can provide an engaging online experience.
It's becoming the most important part of any video game console - Microsoft's Xbox Live is as much a part of the Xbox 360 experience as anything else, and Sony's Playstation Network is used by a significant portion of the PS3 user base.
Nintendo seems to be banking on a very social experience with the Wii U's online service, Miiverse, but it hasn't talked much about exactly what kinds of online content and services will be available.
For a system that's only a few months away from launch, there's still a lot about the Wii U that we don't know. Hopefully those details will be revealed soon.