I went into the Info Center and asked one of the employees there a bunch of questions about Montepulciano's participation in the filming. She hadn't heard of the books, but she said she did notice that they were going to be particularly busy during that week, despite that usually being a fairly quiet tourism time for them. She said that she had been handling some of their hotel bookings, and that she was also helping out booking accomodation and other odds and ends for the film crew.Read the full account of Maggie's Montepulciano adventures! :-)
It was clear pretty quickly that she didn't know what the town was in for. I told her I had heard about a gathering of the Italian fans that was going to take place at the end of filming and she just said 'that's nice. We're excited about the tourism.' It will be neat to talk to her after the filming, and again perhaps a year from now to see how tourism has increased due to the Twilight connection.
Thanks to Ms. Pillowbiters for the heads-up, and to Twilight Lexicon for helping to share Maggie's story with us.