Dr. Doom, you're talking about 2 different things. New Operating Systems (exciting) and upgrading (not exciting).
Being excited about new operating systems is standard fare, just like updates to other software. It's perfectly natural to be excited about being able to do new things with the software, and every new OS has new features (except for WinMe, which never should have been made).
But upgrading to a new OS is completely different. Generally, your computer was built to hardware specifications of the OS it came loaded with. I almost never recommend OS upgrades outside of service packs because, generally, you can't take full advantage of new technologies with old hardware.
So the only time you should ever get a new OS is when you need and purchase a new computer. And since computers are cheaper than cars and have a much shorter shelf life, your productivity will increase with a new computer every 2-3 years, which generally coincides with new OS's.
