I was looking at the Nintendo store launch video, and Charles Martinet was in it and I decided to see to what other games he has provided voices to, and look what I found on his IMDB:
It says he’s providing the voice for Super Mario Galaxy 3:
http://www.imdb.com/name/nm0553409/
And here’s the SMG3 entry just in case it gets removed:
http://www.imdb.com/title/tt5311510/
Again, I don’t know how official this is, but I believe you can’t just add a new movie/game or credit to an actor if you are a regular user, it has to come from someone official, be it either an IMDB employee or a production company or agent.