You might want to look at the Freescale Freedom Board. The cost of a SolderCore is approximate equivalent to an Arduino Uno and an Ethernet Shield combined, and you don't lose any I/O in the process. I ported CoreBASIC to the Freedom Board and it runs acceptably quickly.
The idea of SolderCore is to get customers using the hardware to do something, prototyping even faster than Arduino. It's a no-hassle way to pop on a shield and have it work out of the box, quickly. Or do add sensors and have them work immediately. CoreBASIC is pretty fast, and the built-in drivers are what make it hassle free.