Check it out: The Playgoer has a list (originally published in American Theatre magazine) of the most produced plays being done at professional nonprofit theaters in the 2009-2010 season.
Top of the list? Local playwright Peter Nachtrieb!
Way down the list: hacks like Tennessee Williams and Thornton Wilder.
On a less cool note, if you are a female playwright and not Sarah Ruhl, better luck next year.