I've spent almost a week staring at a screen feeling I had nothing to say or add to IndieCade while writing the keynote for tomorrows event opening. I often feel that way, too. It's called impostor syndrome, and while it might feel like it's a reasonable worry, it simply isn't true.
Everybody that creates, thinks along or engages in our industry in any way adds something. There simply is no way to add nothing. Every person you meet, talk to or befriend is changed forever. Everything you make will impact at least yourself - even if it fails completely - and through yourself the people you talk to, the people that play your games and the people that learn from it.
The first thing to do is start making things. Stop trying to become a game developer and become a game developer. The difference between trying to become and being a game developer is making a game.
In other words: set a deadline for yourself. Make a game every week, or every two weeks - any game at all - and post it on the internet independent of how good it is. Make mental notes about the project. Ask for feedback. Be as open as possible. Try and vary your goals each week: one week make a top down action game, the next week a subversion of text adventures, the next one a boardgame.
See what things interest you and start talking about those publicly. At first, nobody will care. Then a few people. Then at some point you'll get a conversation going. See what interests you about that conversation, and figure out why. Always keep asking yourself 'why'? Why is the big question. Why are you interested in something, and why that specific thing. Why do certain ideas attract you more than others? Why are some conversations more important to you than others? If you want to be creative, you'll need to somewhat understand yourself before you can channel that into a game.
If you're hesitant about something like that, you might want to read this blogpost by Adriel Wallick, a developer from Boston to whom I recommended the same thing. http://msminotaur.com/blog/?p=108
Feel free to e-mail me at any time if you ever feel a bit lost, or if you think you've made something special, always feel free to tag me on Twitter at @tha_rami
Best of luck!