I think we'd pretty much be in the same spot we are now. Most of the aviation advances happened during the two world wars or because of the cold war. If Orville and Wilbur hadn't flown, somebody else would have shortly. But had we not had WWI and WWII, a cold war and space race we would be in a very different spot. Aviation would probably still be a novelty had we not had wars.
And to answer your other question, I went to the Miramar Air Show this weekend (10/18/03). It was great, the JSF mockup was there as well as an FA-18E. And as always the Blue Angels were incredible. Next weekend we are off to Edwards to see the F-22 and the T-Birds.