He seems to know what is doing as far as Iraq and Afghanistan go, the Georgian/South Ossetian situation i am not so sure [similarly with a few others].
Obama sold his wider story, and showed McCain in a less than favourable light, if there was something lacking it was specifics about what a President Barack would do.
He touched on all the topics that he needed to which is all he could do since these types of speeches don't allow candidates to get too far into the weeds due to time constraints. I'm sure the specifics for both candidates will be addressed in the debates.