My previous post which posited that the old yarn that knowing the business domain is a more important skill for the programmer to improve than programming-specific skills is bunk has been partially validated by Joel Spolsky in this podcast.
In it, Jeff Atwood holds the opposing position, but Spolsky's comments were spot on. He did some significant work on a medical application w/o caring a whit about the medical field. I maintained an application which illustrated annuity performance w/o much caring about the specifics of annuities.
I just cannot understand Jeff's position. The specifics of how a given business works is brain filling fluff whereas programming related knowledge is a programmer's bread and butter.
I'm currently working on software which supports educational institutions, but learning more about educational institutions is never germane to making our software better.