For many years, my wife commuted to San Francisco and frequently lamented that there wasn't a cart or other option for picking up a quick dinner on the way home, or on the way onto the train. I always felt that the station area would be an ideal place for such an enterprise.
My experience with the food trucks is as follows. When I work in NYC trucks bring a variety of cuisines. Some have cult followings and you need to track down their locations on a day-to-day basis. I've also tried the trucks that sit in front of the Willows Market on Monday nights. It's somewhat a community event.
Food trucks are not likely to poach customers of the white-table restaurants such as Trellis, Vida, Left Bank and Carpaccio. We are more likely to frequent Santa Cruz Avenue restaurants. Over the years I've spent A LOT with these downtown restaurants, including hosting family and business events. The trucks and the downtown restaurants address different markets, provide different experiences, and different timing. And alcohol. You don't need reservations for the food trucks.
The only restaurant that I can see with a legitimate potential beef with food trucks is Café Borrone. They are about to open a take out pantry next to the café. Borrone is usually closed Sunday and Monday nights. I propose restricting the permitting of the food trucks to those nights. If Santa Cruz Avenue restaurants wanted counter the truck phenomenon I suggest that launch some Very Happy Happy Hours. I'd be pleased to consult on their menus.
Bring 'em on.