My friend Janie Clayton linked to this article by Don Denoncourt, which has some interesting thoughts and observations.
Something with which I agree:
I’ve seen too many people lock themselves into technologies (like Lotus Notes and Domino) and find themselves unmarketable after spending 10 years in that industry. Even if you have a high-paying salary, don’t let the tech world pass you by. Be sure to be up on the latest technologies. And, if you can’t do that at your current position, maybe it’s time to move on.
The entire article is worth taking your time to read.