Before I panic at any poll news, I check to see if it's polling likely or registered voters.
Rule of thumb: Romney leads in likely voters, Obama leads among registered voters. Look for an LV or RV to figure it out. In 2008 RV was a more reliable predictor of final turn out. Most projections show turn-out will be a little down this year, so the final results will be somewhere between the LV and RV numbers. In other words, a damn-close final number, depending on the breaks over the next three weeks, with Obama currently enjoying a slight advantage in the Electoral College math (because Republican voters tend to be hyperconcentrated in low-education Red states).
It's disconcerting to see a Romney 51-Obama 48 swing-state poll here and there, but it's not a strong predictor. The swing states do not vote as a block. Essentially Romney still has to sweep all three of the big purple states (Ohio, Florida, and Virginia) to get to 270. Obama just has to win one of the three to block him.