Another idea:
The way it is now, Cody is just a robot that blindly obbeys everything he is told by Palpatine.
In my last post I criticized the pacing of the movi right after Anakin turns. Said that right after Anakin's first strike you just need to see what happening withe the other characters (for a matter of contrast... "okay, Anakin fell, but what's up with the others?").
So this is my suggestion:
-Palp tells Anakin (in his office) what to do... "the sith will rule the galaxy, etc."
- Cut to somewhere else (am I the only one that feels it's too rushed how far Anakin gets to do his "first strike"???
- Cut back to Anakin first strike with your amazing new score. After this comes the part when I say we need to see another important character ... ok here's the novelty: that character is Palpatine. The idea would be: "while Anakin is killing people, what is Palpatine doing, sitting in his office??": NO.
SO:
- Cut to Palpatine telling Cody "execute order 66"
- Cut to somewhere that's not Utapau.... maybe Padmé criying when she sees fire in the Jedi's.
- Cut to Utapau. ObiWan reunites with Cody, and then Cody shots him.
THE DETAIL: Cody would be giving him his lightsabre! And he says I think you'll be needing this! Left to the viewer's interpretation whether Cody was helping ObiWan or not.... If this is done well, you would have just made another character a little more deep!.
Besides, this way it'd be better, because you'd be generating another tension. You see what happens to Anakin and in the middle of it, you see the emperor telling a clone commander to "execute order 66". So it makes you wander what's gonna happen with ObiWan. There you generate the tension, but again, you put something in the middle: Padmé's scene, and maybe more (the more the better).
And when you come back to Utapau, you see the Clone might have developed some affection (?) for his Jedi General...
Maybe they developed such an affection because he chose to serve? ;)