There are a ton of these type of Arduino devices on the market[0], although this one seems pretty featureful.
I think for something like this to be successful, it needs to be low cost, open-source, and have strong libraries and documentation for beginners. Products like this also tend to have a small, tight-knit community of enthusiasts. Holding a contest with prizes is often a good way to pull in users.
Seems like a very cool project!
[0]:
http://arduino.cc/en/Main/ArduinoBoardEsplora
http://shop.evilmadscientist.com/productsmenu/tinykitlist/10...