I the comments section of the FAQ, one of the team says: "We haven’t made a decision on open hardware yet. We have SPI, I2C, UART and a fair bit of GPIO at 3.3

I the comments section of the FAQ, one of the team says: "We haven’t made a decision on open hardware yet. We have SPI, I2C, UART and a fair bit of GPIO at 3.3V if you want to do interfacing." http://www.raspberrypi.org/?page_id=8#comment-89 http://www.raspberrypi.org/?page_id=8#comment-89 So it sounds like it has as much I/O as you're going to need for embedded funtimes.