Satoru Iwata has given us a little bit more details concerning the way Nintendo is going to be handling the friends list situation on the upcoming Nintendo Wii U. Here is what Iwata stated:
On the Wii U, you can become friends with people who share your tastes through the Miiverse, so increasing the number of people to enjoy games with is its critical mission.
So, it looks like it is going to be somewhat easier to register friends on the Nintendo Wii U in a way. You will be able to friend people with similar interests as you through Miiverse. Not really many details about the specifics though. Do you both have to enter friend codes or do you just click an add friend button? Expect more details about Miiverse in a Nintendo Direct presentation before the Wii U is launched.