I didn't do any shadowing, and don't have much leadership experiences,
I have done tutoring, and did some 30hrs non-medical community service.
It would be silly to apply with so many holes in your application. I recommend you make the needed improvements and apply in June 2011 in that case.
Keep in mind that 50 hours of shadowing is about average; i recommend you aim for 60-80 hours, split among 2-3 doctors, of which at least one is primary care. You might ask your own physician, those of your parents, or docs you've met while gaining clinical experience.
Find a cause you care about and give 2-3 hours of your time each week if you aren't already involved in some nonmedical community service. Examples are soup kitchen, homeless or womens shelter, crisis hotline, teaching ESL to immigrants, after-school tutoring at a middle school or HS, Habitat for Humanity, etc.
Take on a leadership role within one of the above organizations, or start a club, or organize friends to collect for a food pantry, clean up campus, make cookies for a homeless shelter, or something you come up with on your own that involves leading other people to accomplish something.
The tutoring you've done can be listed under Teaching on the application. Good for you!
How are your LORs? Do you have two science faculty who've taught you, one nonscience faculty, and a research advisor letter?
Any chance of a publication in the next 9 months, or another presentation or poster (though it's great you have one already)?