Ann Thompson at her Risky Business blog has been detailing what she calls “an unexpectedly insane feeding frenzy” at the Sundance Film Festival. Midway through the first weekend people were saying that this seemed to be a weak year at Sundance and that sales would be slow. Then, all of a sudden, a number of unexpected titles caught the fancy of audiences and distributors. There has been one big sale (Son of Rambow to Paramount Vantage for $7 million), several medium sized ones (Grace is Gone and Dedication, both to the Weinstein’s for $4 million or so), and heartening pickups of low-budget indies like The Signal (to Magnolia for $2 million) and Weapons (to After Dark Releasing for $1 million). Add to that strong showings by films like The Savages and The Year of the Dog, both of which entered the fest with distribution but looking for critical and audience support, and it seems like a pretty good year…