Gallup had an interesting poll recently showing a marked increase in approval for US leadership under President Obama. The poll found that there was a 51% median approval for US leadership under the current administration. This contrasted with 34% median approval under President Bush.
Remember, this is a poll about perceptions. It is unclear if Obama's foreign policy is all that different from Bush's. In fact, on many controversial topics like the international criminal court, Kyoto, and Guantanamo, Bush policies have been embraced by the current administration.
The results are particularly striking in Europe, where a visceral hatred for Bush rather than reasoned argument seems to affect perceptions about US foreign policy: median disapproval fell from 57% in 2008 to 20% in 2009. Median approval rose from 19% in 2008 to 47% in 2009. What explains this change? US policies have been relatively stable over this period. There is no doubt that Obama's likeability factor has translated into more approval outside Europe as well.
Here's a chart showing select G20 countries: