Pietra Detassis editor-in-chief of the monthly 'Ciak' has confirmed this on her blog:
"'At lunch in Los Angeles with one of the producers of Summit Entertainment, responsible for 'Twilight' and now 'New Moon', the sequel of the saga taken from the books by Stephenie Meyer, explodes this bombshell: Despite the announcements, anticipation and generous offers from every kind of Mayor and Municipality, the vampiresque sequel will not be shot in the romantic places of Volterra, but in Montepulciano where the troupe has found 'the most beautiful place to film'...
In the cast will be present the actors of the first film 'Twilight' Kristen Stewart, Robert Pattinson, Jacob Black and the new entry Dakota Fanning.