Tonight was the night that Epic Game's designer Cliff Bleszinki would unveil Gears of War 3 on Late Night with Jimmy Fallon. We presume it was Gears of War 3, but perhaps it's a new Jazz Jack Rabbit game.
Whatever the unveil was it's been bumped due to a scheduling conflict as the show's producer claimed there was a scheduling conflict with Justin Bieber.
The truth of the matter is Epic wanted to polish what they were showing, so they threw the bun back in the oven for a few more days. Reset those TIVOs, new time is 12:35AM EST on April 12th for the big reveal.