I can't imagine a more unbiased analysis than what Rasmussen said in this article. He even said the incumbent is generally expected to lose some ground in the final weeks. It only makes sense that as the challenger gets more well-known, he will gain some support.
IMO the race hasn't even begun until the first debate. Problem is, Romney's performances were so weak in the primary debates that he suffered big losses after getting hammered by Newt and Santorum in them, and he wanted to stop doing debates by about February because he knew they were likely to go against him. He did manage to do two good "comeback" debates against first Newt and Santorum, but only after suffering huge election losses to them. His natural tendency was not to be tough with his opponents, until they had made him suffer a big loss. So, in a way, the best place for Romney to be going into the first debate, based on his history, is in a losing position in the polls. I just hope it doesn't take losing the first debate for him to decide to make a "comeback" play. And he won't have Ron Paul to play tag-team with like they did against Santorum especially.