EDIT: Summit just added another one:
Cincinnati: Kiowa Gordon

This is just in from Summit Entertainment's Twilight twitter: Several actors from the New Moon movie will be making appearances at a few New Moon DVD release parties! The ones they've announced so far are...

New York City: Peter Facinelli

Pittsburgh: Edi Gathegi

Atlanta: Chaske Spencer & Tyson Houseman

Seattle: Melissa Rosenberg

Salt Lake City: Mike Welch, Christian Serratos, Justin Chon

Denver: Charlie Bewley

Phoenix: Elizabeth Reaser

They haven't given details yet on exactly which parties they will be attending, but we will let you know as soon as they give any more details.