If you watch the presentations at the conference you will realize that none of the ideas are what you would call “world changing”. Almost of all of them are simple ideas with great execution. And these are the top 50 of the many ideas submitted. The point I’m getting at is, don’t wait for that world changing idea to start on your project. Pick a problem to solve and go after it with all you got.
Update: Here is a post by Sarah Lacy where she says that we didn't see any world changing idea at TC50.