niloumat,
Every year, Admissions receives applications from far more talented applicants than it is able to accommodate in a given class. In the past, several applicants who did not receive invitations to interview successfully reapplied in subsequent years. I would highly encourage you to do so if you feel it makes sense.
Unfortunately, due to the sheer volume of requests for feedback, Wharton is no longer able to offer specific feedback (as far as I am aware). To be fair to all, Wharton has decided not to give detailed feedback since it cannot extend such opportunities to all seeking such guidance.
That being said, I recommend that you have a trusted and experienced third-person/friend (e.g., someone who is a current MBA student) look over your application materials to provide objective, critical feedback. While I cannot say if this is true in your case, I would note that several applicants find that they could have done a better job getting to know themselves, their motivations for applying now, and expressing how a Wharton MBA will particularly help them along their career path.
Though this is easier said than done, try not to be less motivated. If you think of this as a potential learning opportunity, then you might have a better chance of success at some other places (or in a future application to Wharton, perhaps).
If you have the luxury of time on your side, I would encourage you to give yourself some time to rest and take a break before revisiting your application with fresher eyes and a more objectively critical perspective. Try putting yourself in AdCom's shoes and thinking through what you would say are your strongest and weakest points - but do this only after you are better able to let your raw emotions pass by you (so you do not get a distorted perspective/result).
Hope this helps. Good luck!
-Victor
WG '11