I started a github project to write a C library to enable working with the pins, doing muxing and more to come.
I am a total newbie to these kinds of project and it is a nice learning ground. As there are more and more people here on the mailinglist who are in the same situation, I welcome anyone to have a look at https://github.com/justjoheinz/beagleboneIO - create a fork and start working on it.
There is very litle there at the moment, as I said. The total aim is to create something almost as easy to use as the Arduino library, or something like the cloud9/nodejs stuff - only in C.
I would be happy if people would comment, either here, or on github. Lots can be done better!