A few reminders to help sort through the possibilities without losing sight of the big picture:
Alex Smith is almost certainly going to start for the 49ers unless he gets hurt. Smith would have to play horrendously to lose his job entering the season. The 49ers have made continuity a top priority this offseason. Even if Carr appears to outplay Smith during exhibition games, the 49ers have too much invested in Smith and continuity to make a change early.
Matt Hasselbeck should be an easy choice for Seattle entering the season because of the experience and leadership he offers. Early returns suggest we should focus less on his competition with Whitehurst than on his ability to stay healthy.
We should expect the Rams to make Bradford their starter at some point during the season, so there's no use in getting too worked up about when the transition takes place.
The quarterback situation in Arizona appears most intriguing. Coach Ken Whisenhunt publicly backed Matt Leinart two summers ago, only to go with Kurt Warner when the games counted. Warner isn't an option any longer, so Leinart should have an easier time winning the job. Keep an eye on how Whisenhunt divides practice reps between Leinart and Anderson.