First

Bush hits 39% in the Gallup - his first sub-40 approval rating in that poll.

(Knowing the Gallup and it's wild swings, I wouldn't be surprised to see Bush back above 40 next week, with Blitzer and friends claiming "the President is coming back!")

...Here's a Gallup trend line, to give you a better sense of the trajectory in the President's approval ratings. And here's a summary of recent polling that shows the dip below 40 is widespread.