A Vocaloid. Its a singing synthesizer program (I think). Miku Hatsune is one of the voices (Yes, it is a japanese thing, although I heard there are some in Europe). ...This commercial was on tv?
Miku is the persona they made for the lyrics this program/synthesizer produces using lyrics and melodies put into the program (Though it can also be specified when to use vibrato, how much of it to use, how long to hold it, when to start it, etc.). One thing's certain; Autotune looks like a child's toy compared to it. I mean, even if autotune was super advanced it would still be used like a child's toy 90% of the time, but you get my point.
EDIT: I just found this, and I cannot stop laughing.