I think that Obama's insistence on keeping the debate tonight has been rather telling. As a Senator, he has an opportunity to enact change right now. However, he prefers to go into a debate and talk about the changes that he would make if he were given even more power. But if he will not create change now, will he create change when he becomes President? According to a collection of ancient Jewish wisdom (cough) "He who is faithful in little is also faithful in much."
As Obama mentioned the president has to be able to multitask. Him hanging out in Washington would not have made progress happen any faster. Instead, he recognized that it was important to get information out to the American people. Remember, we live in a day and age where you can get anywhere in the US in a couple of hours. He was talking with the rest of congress in the morning and then took a plane. This isn't that hard of a concept.