UPDATE: Website AllGamesBeta has posted some leaked screenshots. They're under the "Read More" tag.
Call of Duty: Black Ops 2 is officially confirmed and it's got a November 13, 2012 release date, as revealed on the newly updated UK version of CallofDuty.com. The official trailer reveal had already been set for May 1 during the TBS coverage of the 2012 NBA Playoffs, and that's still happening tonight. There's a YouTube window for the trailer on the Call of Duty website, but it's obviously not playing yet.
Peeking into the source code for the page, you can see this brief description of where the game is headed: "Pushing the boundaries of what fans have come to expect from the record-setting entertainment franchise, Call of Duty: Black Ops 2 propels players into a near future, 21st Century Cold War, where technology and weapons have converged to create a new generation of warfare." There's also a link in the source to a thumbnail image (enlarged above) showing a helicopter flying toward a war-torn Los Angeles in what appears to be a newscast.
Call of Duty games traditionally share day and date UK and US releases, so expect the same to happen with Black Ops 2 this fall. And of course stay tuned for the upcoming full reveal.