mac users and feeling the need to upgrade

Ive been an avid mac user for, oh I dont know, a week now. But I have had an ipod for 4 years now. Every year it seems I buy a new one to keep up. I think apple has a little more to offer when an major update happens than other manufacturers. I am perfectly content with using something until it dies. But ever since I have been using my macbook I am always waiting for the next update (hell, im already thinking about getting an imac for my desktop system).

I guess my question is this, do you guys find yourself updating your system more than a PC user would? Do you guys feel that Apple makes it worth your money to upgrade every 2 or so years? I see people running on PCs that are 5 years old but I never see people with outdated macs. When a new major model change comes out it seems that people will instantly jump on it