You can't judge Bynum yet. He's 18 years old. The youngest player ever drafted into the NBA. You don't want to trade him to another team and watch develop into a top flight NBA center. Give the kid some time. He wasn't drafted to help the team in the immediate future.
The only untouchable players are Bryant, Odom, and Bynum. The Lakers needs to get a point guard who can shoot. Quincy Douby would be a nice fit for example.
They need scorers to come off the bench and they need youth. Kareem Rush should come pretty cheap and he can help right away. He's familiar with the system.
If Phil is moving Odom to Power Forward, the Lakers need to get someone to play the wing alongside Kobe. Caron Butler would've been nice. Luke Walton isn't good enough. If the Lakers can trade up to get Shawne Williams from Memphis, they should consider it.