Larry 'Major Nelson' Hryb has posted a live countdown to E3 2013 on his official blog, sparking web speculation as to the nature of the hint.

Hryb, the Director of Programming for Xbox Live, posted the counter at 8:51am PT on January 2. It is accompanied by the tease "and it's on...".
While it's unusual for a representative to initiate E3 hype this early in the year, 2013 is widely believed to be the year both Microsoft and Sony will release their next-gen consoles.

Whatever it is, we have approximately 159 days to wait until we find out.