Amy Wohl has been writing about user interfaces in her developerWorks blog as well as in her "Amy Wohl" blog. I have known Amy for a long time, and have always enjoyed reading what she has to say, as well as talking to her on a variety of issues from programming environments to IP strategy to cooking.
Amy is exploring a very important point, namely that programmers, almost universally, are not the best people to design applications and interfaces for use by "normal" people, i.e., people who are not programmers and who could care less about programming, computers and technology. Amy includes a link to a really funny story on what a house designed by software developers would look like. Her key point is that programmers think one way, and most users think a totally different way.