I can't do anything today. I'm just sitting/laying around checking my email every 2 minutes. Halp.
My suggestion would be to map out the next six hours of your life. Just six hours. You can do that, surely. Then execute them. FLAWLESSLY, and exactly. When you're done, come back, and see what YC had to say. But whatever they say, you'll have a sense of real confidence that you can execute -- and that you don't need YC's permission to be a success.
Doesn't matter what it is -- hack some code, smile and dial, go for a run, read a book, whatever. But EXECUTE, and you'll feel better.
And to all who applied -- good luck! This isn't my first rodeo (in terms of YC or startups) and I can say for sure that a.) YC isn't right for every company at every stage and b.) there's a lot of ways to skin a cat, so keep on truckin!