Have you been waiting for the the FEZ announcement? … Very soon my friend, very soon!
A commercial grade maker device with premium support and is Fast&Easy (FEZ) to use. Plus you can also use it to have fun with the kids. This example uses Pololu Robotics and Electronics awesome Zumobot. And here is the code GitHub - ghi-electronics/TinyCLR-Samples: Sample projects and demos for TinyCLR OS
Zumobot uses reflectors to detect the surface it is on. Can be used for line followers, maze solvers and to simply dance on a table without falling off.