After a slow couple of weeks, the pollsters have been very busy in the past 48 hours:
So, what's going on here? A pretty decent set of results for Obama -- but also not ones out of line with our expectations. South Carolina and South Dakota are relatively competitive? We knew that based on how North Carolina and North Dakota had been polling. Iowa looks out of reach for McCain? It's looked that way all year, with the exception of one or two polls taken during the flooding. Obama's numbers look pretty good in the CBS/NYT and ABC/WaPo national polls? Those pollsters have tended to show relatively favorable results for the Democrats all year.
So what looks like a pretty interesting set of polling is really more of the same. Obama is polling a bit of his peak numbers (note that the trendline adjustment now tweaks his numbers downward in states like Florida), but he retains a meaningful lead in the popular vote and some structural advantages in terms of the electoral math.
(Full disclosure: I also caught a small bug that was failing to roll in the trendline adjustment properly in recent days and also overstating the third-party vote. This was inflating Obama's popular vote margin by half a point or so. It has been corrected.)