Not particularly. A large percentage of iPhone 4 buyers are upgrading their iPhone. I'm guessing you don't have an iPhone.
In my situation, I use my iPhone a lot. It is my one most-used piece of technology. Work, email, phone calls, IM, games, etc... it gets a ton of use. And I suspect it's the same for many, so I think the excitement is genuine.
I don't know what you do day to day, but let's say you were a painter, and you particularly loved this one brand of brush that you used all the time, and a much better version comes out, you'd want to get it today. Not 4 weeks from now.
Similarly, people line up for sporting events. There's no sport I care enough about to do the same, I don't begrudge them doing it.
arn