I think people have noticed that having smart and efficient backups in the league is a good thing. Take a Dilfer for example, no one expected him to do much when he had to step up for a couple different teams and get in there to play. And he didn't do much, except minimize mistakes, lead his team, and move the ball (ugly at times). Led the Ravens to win the title game in the process.
I don't realistically think Craig will ever be a guy that a team gets excited about being their starter (not unlike Dilfer), but I think he's someone they can feel good about if their #1 goes down for short(ish) periods of time.
It's worth pointing out that I'm not saying Craig is going to lead someone to the big game as a backup, just that sometimes smart and mistake-free are more appealing backup qualities than a big arm.