Based on review of the USPTO webpage statistics today, the PTO should still be accepting green tech petitions for accelerated examination. The PTO had declared in December that they would stop the program upon granting of 3,500 petitions, or upon reaching the date, March 30, 2012, whichever occurs first. As of the statistics posted today, only 3,375 petitions have been granted. Hence, the program should still be open, in theory at least. However, caution: the statistics also show 335 petitions are being considered, so if a petition is filed now, it may not be reviewed in time.
When this program expires, patent applicants can still file for a track I accelerated examination.