Hi lucky,
Thanks for the kind words. I've been programming for almost 20 years professionally. I'd highly recommend any INTP to seriously, very seriously consider taking it up. Yes it's not perfect - yes it's better then anything else you can put your hand to. I know, I've had a number of careers.
As to the validity of MBTI, my son happens to be an INTP, and all I can say is that my nose is rubbed in the truth of MBTI every day.