It seems that it did somewhat increase good will toward America. I don't have any solid evidence to base that on, but it looks like the worldwide media reaction was generally favorable.Talk, schmalk. Anybody can talk about peace.
I didn't hear his Cairo speech that a few posters have referenced. I would ask, what tangible evidence do we have that that particular speech did anything? Besides it sounding good, what did it actually accomplish?
Some outright nasty people have won the Nobel Peace Prize. Again, it's used as encouragement.I don't know how anybody can make a rational argument that Obama has done anything even remotely close to the above examples.