In the polls out there, you have some that have Obama +3 or +4, some tied, and one McCain -3. Since one expects a variety of numbers at any one time, roughly grouped around the actual %s in the population, it looks like Obama is up around 2 points right now in the national numbers.
None of that matters. Most people don't pay attention to polls anyway. Frankly, I don't think they ever have. In 1936, the most well known "poll" (in parentheses because it didn't use random sampling), the Literary Digest poll predicted a huge Roosevelt loss and he had a huge win. There is no bandwagon effect.
I don't have time to look this up now, but both http://www.fivethirtyeight.com/ and pollster.com have done rigorous analyses to determine which polling operations have done the best job in the past. I can't recall precisely, but I believe Gallup was not in the top tier. Furthermore, Moore over at Pollster recently did a careful analysis of the Gallup tracking poll and found that is figures were consistently below the nontrackers.
I've always thought that they discredit themselves. Not long ago, I saw Will Bower say that he was going to vote for McCain because he didn't like the delegate allocation formula the Democrats use. It's hard to imagine that anyone thinks that's a rational basis for a presidential vote.