You might want to have a lok at the Atmel STK-600 board. Its a generic board with lots of headers, 8 LEDs, 8 buttons, RS-232, USB, CAN... It works with all of Atmel's processors. To use you, you also get a card specific to the form factor of the uC, for example, a card that accepts a TQFP-44 uC. They you get a routing card that is specific to the uC. They you mount the socket card on to the routing card and the routing card on to the STK-600 and you have one cool prototyping hardware system.