I am married for 3 years with a American guy,my 2 years green card will expire in August 2012. We apply already for the 10 years green card but now we want to divorce what happen if we divorce before I receive something from immigration?

If any part of your application is fraudulent you can be deported.

I believe you are asked if there are any changes before your "green card" is renewed. You need to tell the truth.