Wayyy too early to start making historial judgements. Truman when he left office was very low in the poll numbers and many thought his was the worst administration ever (some Dem's included). Yet, he is now considered a 'near great.' An opinion I hardily agree with. Eisenhower who followed him also was now judged as a very good president, but he too, has come up in the "historians" polls.
Altho, to be completely candid, I was thinking that same thought (Bush's presidency) today when I read he apologized to the Chinese president for the heckler. Hmm, a heckler who complained about the lack of religious freedom in China and Bush apologizes for the interruption?