Tonight's polls are courtesy of Rasmussen, which has cycled through to Nevada and North Carolina. McCain leads both Democrats in North Carolina: Obama by 9 points and Hillary by 16. And both Democrats lead McCain in Nevada: Obama is winning by 4, and Hillary by 1.
This is a fairly neutral batch of news for everyone involved. The 1-point lead that Clinton holds over McCain in Nevada is her best result in any public poll of that state; but, her 16-point deficit in North Carolina is her worst result of any poll in that state. For Obama, both polls are fairly close to his established averages.
It's interesting to ponder whether either Democrat would decide to devote resources to North Carolina in the general election cycle. North Carolina has dropped entirely off of Clinton's swing state list, and fallen to the bottom of Obama's. On the other hand, both Democrats will be building a ground game in North Carolina in preparation for the May primary (arguably the most important primary remaining in terms of media narrative -- including Pennsylvania).
North Carolina is going to be surveyed frequently, as both Civitas and PPP put out polls on a monthly basis. I'd say that Obama (or Clinton) needs to poll within the margin of error in at least one or two of those polls between now and May for North Carolina to qualify as a bona fide swing state.