Cliff Bleszinkski (the game developer previously known as CliffyB) has tweeted that he'll uncover two new games when he visits Jimmy Fallon tonight (or tomorrow morning, depending on where in the world you're located).
"NEWSFLASH: Two announcements about two upcoming games on Monday. BOOM!", he wrote.
The two games are expected to be Gears of War 3, which Microsoft accidentally revealed on Xbox Live last week, and Bulletstorm (made by People Can Fly, creators of Painkiller and the PC-version of Gears of War).