During a shareholders meeting yesterday, Nintendo President Satoru Iwata said that there will not be a fee to access the Nintendo Wii U's online services.
A general translation of his comments by Andriasang reads, "Iwata said that he doesn't necessarily reject the idea of a paid service that allows not just Wii U but various other devices to connect to Nintendo Network. However, when considering Nintendo's users, a paid membership service is not the best approach. By having everyone use the Miiverse together, word of mouth will more easily spread."
He added that he believed word of mouth gained from a higher user-based would lead to higher overall sales. In the presentation he also noted that there are no near-future plans for a new model of the 3DS beyond the 3DS XL. He cited concerns about mass production efficiency in his explanation.