Robert Hanson on my million dollar Q

Robert Hanson writes about the million dollar question I have been asking to myself for long time. Whats the standard practice to learn/adapt new technologies. It is good to learn new technologies. But there are toooooo many new THINGS ! . Like he mentions on MVC, how many MVC I have gone through last year or so ? From simple JSP to Struts, JSF , spring MVC and take GWT if you wish. Sure, I learned these THINGS and that helped me to improve my skills. Every models have their own pros and cons. But will this be effective ? Can we make full use of these technologies if do continue like this ? It is true that these things are evolving and there is always a superior THING on the corner. But my questions is (Or rather lots of people's Q is), when should we do this ?

I think it is the question of how the existing technology meet our expectations and how good the new technology would help to improve our solutions. I think our temptation to learn new technology (Or on our thrill on use new technologies) often beats and we skip to answer those questions and just do it.

Any comments ?