"An- and every corner has a schoolgirl panty vending machine and samurai are so cool and hundreds of thousands of people adore a synthesised popstar!" that odd otaku acquaintance of yours urges. They're not entirely wrong, factually and morally--just mostly. Soon we'll get to meet Japan's virtual popstar Hatsune Miku, as Sega has announced it's bringing her game Project DIVA F to western PS3s in August.
Hatsune Miku is a virtual popstar, whose voice synthesises words based on samples from an anime voice actress and whose physical form is, well, a teenage anime girl projected onto stages at live shows. What makes it so thoroughly delightful is that the Vocaloid software which gives her a voice is sold freely, so anyone can write songs for her to sing. The future is amazing.
As for Project DIVA F, it's the fifth in her series of rhythm games. You do things in time to the music. Rhythmically. You can also create music videos and customise Hatsune Miku's look.
You won't even need to wait until August to meet her, as a demo lands on June 11. Any further questions? This trailer for Japanese version surely answers everything: