While Wii Music was not the blockbuster hit everyone at Nintendo had hoped it would be, they likely aren’t taking it lying it down. Nintendo is possibly planning a sequel to Wii Music at some point.
Edge Magazine had an interview with Nintendo developer extraordinaire about his feeling of the family music game he helped develop and about the possible sequel:
“As soon as we’ve finished a project, I always have regrets about what we could or should’ve done,” said Miyamoto in the interview. “But then there are these great ideas that we can utilize with future projects, one way or another. Some people might say Wii Music is a good example. It’s been said that it could have sold much more than it actually has to date, but it simply means that I have some assets right now that, by tweaking something, we might be able to have great success with in future.”
Essentially: Miyamoto believes that the title could return as a full sequel or half-sequel like Wii Fit Plus.