The schedule for the 2013 Game Developers Conference indicates that we won't have to wait too much longer to find out more about Bungie's new project, listing a lecture from the acclaimed studio, titled "Brave New World: New Bungie IP" that will discuss the challenges of their momentus new task (via Polygon):
The presentation from design director Joe Staten and art director Christopher Barrett, both of whom are 11-year Bungie veterans, will give attendees "key insights into Bungie's battle-tested design process" and a look at the studio's "world building techniques, from concept to production." Staten and Barrett will also offer a look at the world of Destiny itself, which the studio refers to as "a place where the next ten years of great Bungie adventures will unfold."It's possible that we'll see a formal reveal before GDC in March, but no other announcements have been made.
A single piece of concept art from Destiny was shown off a couple of months ago following a leak of some game details by way of early marketing material.