What started off as a meme, has turned into a near reality. When the E3 trailer for Battlefield 3 was released this summer, it started off with a soldier holding up a dinosaur statue. Obviously, this means that DICE (the developers) should release a DLC pack where you're fighting dinosaurs. This is the next best thing, I guess. DICE, if you're listening, I've got loads of ideas for the dinosaur DLC.
To find the Easter Egg, load up the level Wake Island (which you'll need the Back to Karkand DLC for), and start on the American side of the map. Down on one of the beaches to the left of your starting point, you'll find a cute little dinosaur figure hanging out under the shade.