I wrote about the Intel Galileo a while back. It's an Intel Quark based device which, as you can buy it at the moment, runs a cut down version of Linux which allows it to behave as an Arduino (it has shield connections) with a high performance backend
At the time I took my first look I was bemoaning the way that the really interesting aspects of the platform (the ones which have it running a variant of Windows) weren't available for shop bought Galileo devices.
Well, that's changed. If you have (or you get) a Galileo device you can now upgrade the firmware and install a Windows based operating system on an SD card for the device to boot from. Upgrading the Galileo and making the boot image are easy enough (I know this because I've done it) and raise the interesting prospect of running full fat Windows programs, created and deployed using Visual Studio, on a processor around the size of your toenail. You can find out more here.