It has to be tough for Jake Locker to sit while guys like Cam Newton and Andy Dalton are having so much success, but you won't hear him complain about his situation (via Jim Wyatt):
"As a competitor you always want to be on the field playing," Locker said. "But I think there is a lot for me to learn in this situation, and a lot that can allow me to improve as a player."
It helps that Locker knew the situation from the beginning, and that he has a good relationship with Matt Hasselbeck, but it still has to be tough for him to sit and watch while other rookies are playing. I think he realizes that this time of sitting and watching is going to really benefit him in the long run.
There are a lot of people who wanted Locker out there from day one, but I think this plan is the best way of bringing him along. He has time to work out the mechanical issues that caused him problems at Washington, and he will be a lot more prepared when it is his time.