I think that Obama technically lost the debate, though I don't think it matters. Debates are all about style, since the substance is always up for debate and Romney was more fluid in his speak and more confident in his posture and tone. He even yelled down the moderator who knows how many times. Americans respect a certain degree of aggressiveness in their politicians.
That being said, I don't think it matters, because most people didn't watch the whole debate. I am making this prediction now, but it is a fairly easy prediction to make. Most people don't watch the debates and this debate was particularly dull and uninformative, so I imagine a lot of people tuned out. Most people have already decided who they are voting for by now, so it is only the independents that may be influenced. Despite what the polls may say in the next few days a 1-2 point bump will not be a game changer.