I understand and appreciate that the Republican base is getting excited because the polls are starting to show closure between McCain and The O. Not to rain all over the parade, but popular vote doesn't mean diddly squat. To paraphrase the resounding theme from the '92 election, it's the electoral college, stupid.
I haven't done the EC math, but I suspect it's possible that either candidate could pull a significant majority of the popular vote (along the lines of 51-49 or even 52-48) and still lose because they didn't win the right states to hit 270 electoral votes. I'm no grizzled campaign veteran, but I can't say I've spent a whole lot of time getting worked up over the latest poll that shows The O up by 8, or 10, or 13 points. Number one, we don't know the pollster's processes (weighting, sample size and distribution, etc.) well enough to put significant faith in the results. Number two, the expansion and contraction happens too frequently as candidates gain and lose momentum during the course of a 10- or 12-week campaign (particularly from things you could never see coming, a la Joe the Plumber). Finally, it's unrealistic to expect that a major party candidate would pull less than 46-48% of the popular vote; polls that show a candidate at 40-44% are simply out of touch with reality.
In the end, the only poll that matters is the EC vote, and we won't know that until Tuesday night at the earliest. So take what encouragement you need to from the tightening polls, but understand that under our system, popular vote doesn't mean anything to the bottom line.