Somebody please make a device which is more accessible (pricewise), and can be used to prototype/interface with common digital protocols (i2c, uart's, spi, CAN,

Somebody please make a device which is more accessible (pricewise), and can be used to prototype/interface with common digital protocols (i2c, uart's, spi, CAN, ethernet, USB). I'd imagine it could be a mashup of SBC (Beagle, Olimex's LIME, heck, even RaspberryPi) and Bus Pirate. Add a screen and battery, and call it a day. I don't think a device like this should have the fastest CPU and plenty of RAM (that wouldn't hurt of course).