you can file to remove conditions on your own. if you do nothing then you might find it a bit hard on yourself in the future with the USCIS. If you leave the country after your conditional green card has expired you will not be allowed back in.
http://www.visajourney.com/forums/index.ph...p;page=751guide7.11) ..My marriage fell apart and we are divorced. Can I still get the conditional status lifted?
A..The I-751 is normally filed by a married couple, but if you have divorced, or your US Citizen spouse has died, you may file the petition on your own. The I-751 form itself contains provisions for a waiver of the requirement to file jointly with the US Citizen spouse. You may file the I-751 immediately upon divorce or the death of your spouse, and you will be required to provide evidence that you married in good faith, rather than to just get a green card by marrying a US Citizen. You will be required to submit a copy of the divorce decree or death certificate.
The I-751 also makes provisions for a waiver for filing jointly with your spouse, if you are still married, but "battered or subject to extreme mental cruelty". If you are in this unfortunate situation, you need the help of an experienced immigration attorney.
Also search the USCIS website for information on removing conditions.
A consultation with a immigration attorney for your particualr case is always a good idea.