I plan on making it pretty open (ssh access over usb) and release the toolchain etc. that I use, but we don't have the resources to officially support third-party applications.
The OS itself is pretty standard Linux distro, but I might end up just using Debian. I also plan to try to mainline as many of the drivers we use as possible.
One of the issues I personally want to solve is the lack of a hackable e-paper device.