The press conference has become an important part of any president's experience; presidents are judged by how many press conferences they hold, who they call on, and most importantly how they answer. As an aside, press conferences are no longer press conferences--reporters are now the media not the press, and it's not really a conference either.
In any case, here's how press conferences work: A man or woman stands in front of a lot of reporters, who are trying to achieve a few things. They want to get information through direct interrogation. They want to look smart. And they are hoping most of all that the question they ask leads to "news"--which means information that the subject of the press conference was not going to reveal.
The subject of the press conference wants to look smart, seem open and willing to talk casually and formally at the same time, and most of all, not tell the reporters anything he or she did not want to say. In other words, it's both a chance for information exchange and a bit of a test of wills.
It's clearly performance on both sides, and the performance is for the subject, reporters, and a variety of audiences, all of whom have rooting interests in the outcome.
In this case, the "news," defined as something new or noteworthy, was more meta--Obama had a good press conference and made his case to the American public. That news has little to do with the substance of press conference but rather its context and style. Indeed, the biggest "news" that seemed to come out of the press conference was the fact that Obama called on a Huffington Post reporter, the type of meta-news that the Internet loves.
The evaluations of Obama's conference make sense if you see the bigger picture. One reporter, John Dickerson said he sounded like a professor. I think it's been a while since Dickerson has been in school--what professor stands in front of the room and takes questions from his students like that--wearing an expensive suit? And why is being a professor a bad thing? (Note: I'm a professor and I think it's a good thing.)
But Dickerson's observation speaks to the larger point that Obama had answers to the questions, as a professor is supposed to.
I agree with Jon Stewart--it was nice to hear answers in complete sentences. And it was an important milestone in a president's term: the first news conference and one in which he seemed relatively comfortable. In the first test of wills, Obama clearly won. But the reporters won too by having lots of written material for their stories.