Japan's Tower Records revealed that anime studio Shaft and director Akiyuki Shinbo have been attached to a project inspired by vocaloid producer's Jin (aka Shizen no Teki-P) Kagerou Project (Heat-Haze Project). The anime will share the name of Jin's first album, Mekakucity Actors. ("Mekakucity" being a portmanteau of "mekakushi"/"blindfold" and "city")
Hinting at the format, they say that the airing date hasn't been decided.
Source: CR