When the rebooted, alternate universe Star Trek movie took simply Star Trek as its title, it broke the mold of titling the films Star Trek: Something Related to the Plot. It appears that the second film is following this colon-free trend, as TrekMovie is reporting that the new film's title is Star Trek Into Darkness.
TrekMovie says that it has confirmed the title with multiple sources, and ComingSoon noted that Paramount has registered the domain names startrekintodarkness.com and startrekintodarknessmovie.com. Paramount hasn't officially announced the title (nor confirmed it), but the creative team is reportedly working on a way to release the film's title visually.
I'm hoping that the title refers to some specific element of the plot rather than a generic darkening of the film's tone. Could the Enterprise crew find themselves headed toward literal darkness? Or is this the promise of a Joseph Conrad send-up where we'll meet Starfleet's version of Kurtz? The horror...the horrror.