I've been looking vaguely at the ATmega1284p for a project which requires pins, not horsepower, and I also came across this, the Unduino1284p. It does not appear yet to be orderable, but looks quite neat:
Atmega1284P On Top (a.k.a. Bobweeny)Modeled after the Solarbotics Ardweeny, but adapted to have the 1284P on wirewrap socket headers instead of sitting under a board and having to solder all the legs to something. Killed your chip? Pop in a new one!