Today’s result is 49/47 Obama/Romney (identical to yesterday), but read on:
These results are based upon nightly interviews and reported on a three-day rolling average basis. As a result, only about one-third of the interviews for today’s update were conducted after the presidential debate. The single night of polling conducted after the debate did show some improvement for Romney, but it remains to be seen whether that will continue or if it was merely statistical noise. Sunday morning’s update will be the first national polling based entirely upon post-debate interviews.
(Bolding mine) This is why Rasmussen (and Gallup) does rolling averages; to damp out fluctuations. Personally, I expect to see Thursday’s improvement turn into a bounce, but Rasmussen’s point that one day isn’t a trend is valid. Good news, in other words, but don’t get complacent.