The "I'm A Mac" commercial series was a light-hearted campaign that people from both sides found funny. As a PC user, I even found it funny. Things feel different in the way Apple are handling themselves these days, after all these years of being on-top, their competitors are finally catching up with a vengeance. Apple have no new product ideas as revolutionary as the iPad or iPhone which were turning points in the portable hardware race that left naysayers struggling to compete in.

Going on the defensive when you feel threatened is a natural human instinct which carries through to the business world as well, it's just filtered a whole lot better generally (unless it's coming from the top as is the case with Cook and Balmer).