Technical Machine, the startup behind the Tessel hardware, aim to make embedded development as easy as building web apps. If the pipeline they’ve designed works as promised this will certainly make hardware prototyping much faster and easier.
The board itself is extensible, with the developers promising plug-in boards for servos, relays, RFID, Audio, Bluetooth, MicroSD, Accelerometer, temperature and humidity sensors. They also promise an Arduino module compatible with Arduino shields and can run Arduino libraries and sketches directly.
Crowd-funding for Tessel production can be found on Dragon Innovation until the beginning of October 2013.