Kristin from E! Online teases this...

"Someone will get engaged.
Someone will get more than that.
Someone will die.
Someone we thought was dead will return.
Two people whose names both start with the letter "A" will get even hotter.
And Grey's Anatomy will do the one thing that you'd think it never, ever, ever, ever could. Yes, that!"

What could possibly be happening?! I'm so excited now! Obviously, the "A" thing is Alex & Addison, and we've heard that Callie & George are getting engaged, but dead - return?! And what will they do that we think it can never ever do?! OH MY GOSH!

Seriously!