It took quite a while for someone to start it, but there is now a Collaborative Piano entry on Wikipedia. Here's the short and succinct description of the field:
Collaborative piano is a discipline of music that combines piano performance, accompaniment, and music pedagogy.Short, but to the point. The description is attributed to a 2014 incarnation of the NYU Collaborative Piano page. The entry has a US-only list of schools, a pretty good source list, and a rather short music festivals list.
Friends, now is the time for you to get to work and collaboratively expand the scope of this article! Add more depth and detail, add some more relevant schools and festivals, expand the range of resources to include periodicals, dissertations, and websites, create a talk page, get the discussion going, and give this profession the exposure it needs. To give you an idea of what it could become, take a look at the well-developed piano pedagogy page.
Here are some quick Wikipedia resources for those keen on editing but who haven't yet got the Wiki skills:
from The Collaborative Piano Blog