Wait for more to see if it's an outlier of course...
Obama Campaign has only really got cracking at PA in the last week or so, plus after the disaster of the Wright affair Obama's speech on race has had nearly universal praise from every news outlet... its not a bad place to begin his recovery from, whats more the Obama campaign would be very keen to enhance it's status in PA as the underdog (somthing they allowed to slip in OH and TX) hence maybe why the last few weeks since March 5th have seen the Obama campaign running a much more low profile effort in PA... it'll be interesting to see what happens now they have to head into a higher gear.