If you sign up here, supposedly Ms will send you a free Intel Galileo dev board.
It's like an Arduino, is pin compatible for Shields etc., but by all accounts it's pretty terrible at basic Arduino stuff (the arduino mode is emulated on top of a linux/windows os). Could be useful for more processing intensive stuff though, and with built in ether net you could serve stuff up straight from the board.
http://msdn.microsoft.com/en-us/windows/hardware/dn786369