GEORGE O'MALLEY IS JOHN DOE
In the season finale of Grey's Anatomy, Izzie survived surgery for her tumor (yes!), but started to slip just as her memory returned (oh, no!). Then, in a tragic discovery, the doctors of Seattle Grace realized a John Doe, who was hit by a bus, was (omg!) George. In the final cliff-hanging scene, Izzie, in the dress she wore when Denny died, saw her friend in his Army uniform, leaving fans wondering who would live and who would die.