I don't think the topic is new per se, as really a lot of software engineering history has been about dealing with the human aspects of development. Even fundamental concepts like object-orientation are grounded in psychology and even before software, there were precursors for this kind of thinking in the way machines and working environments were designed. Josh Bloch's Effective Java is a more recent example.
The difference now is that UX has become a popular, well-understood, discipline. So we have a lot more concepts to take back into API design.
Some of us have been capturing relevant links on the topic on a Developer Experience page (https://plus.google.com/116834904360889286443/posts) and under the #devexp hashtag. We don't have t-shirts, but we do have a logo in need of much love! I'll go add a link to that presentation too.
The difference now is that UX has become a popular, well-understood, discipline. So we have a lot more concepts to take back into API design.
Some of us have been capturing relevant links on the topic on a Developer Experience page (https://plus.google.com/116834904360889286443/posts) and under the #devexp hashtag. We don't have t-shirts, but we do have a logo in need of much love! I'll go add a link to that presentation too.