I know it's Sunday, and a holiday weekend, and all, but I think it's still worth noting that....
Guess what? Obama's back over 50. Gallup today has the president at 51% approval. He wound up (for now) spending a bit over a week at either 49 or 48%. I believe this is technically a record for Gallup (fasted recovery over 50% after first time dropping below), but as I said last week such records are meaningless, because Gallup has never before done daily tracking.
It's worth noting that in the old days (before Obama), there have been plenty of periods longer than ten days that Gallup did no presidential polling. If it turns out that Obama sticks above 50% for a while, then had Gallup only polled on November 1 and December 1, they never would have caught the "under 50" period.
On the other hand, Gallup could easily have registered a sub-50 number as early as August; it's probably just luck that he never slid below that mark for a three-month stretch in which he repeatedly came close.
As always, the best place to go for approval ratings is the pollster.com trend line, and as always, use caution even with that number, because it will change as new data show up (and the approval number is pushed pretty hard by two daily tracks, the Gallup and Rassmussen polls).