It really does have fantastic potential. I don't understand why Arduino proper hasn't picked it up for an official board. I see it as more applicable than the Mega in many cases, and certainly easier to use in DIP format. For all you get (RAM, raw I/O, various dedicated hardware serial I/O, flash space), it's dirt cheap, too.
+1 for that... 
RAM + no. of I/O is what attracted me to it... still now couldnt get it to make it work smoothly though... 