Rivers did nothing today in a meaningless game against a disinterested opponent.
His trade value is based on his previous salary (two years ago) and his time in the league versus what a Top 5 (Leinhart) will command in new 2006 $$.
I think that most teams that were interested in trading a 1st rounder for Rivers would have liked to see better play from him. As I said, at best it's a "wait until next year," but that won't help move Rivers THIS off-season. And many times, the potential of a rookie outweighs the known of a guy who has played in the league (although essentially a rookie, he's been in the league 2 years). Just look at Travis' trade value last off-season for proof of that.
After seeing the injury, I'd be surprised if it were just a separated shoulder. But even if it is, he likely won't be healthy/ready before the decision to franchise him rolls around, and casts uncertainty on what to do with him, and limits what the Chargers can do with Rivers.