Also have a look at the Cygnal Chips. They are Michael Karas's favourite , and I must admit that I am warming to them aswell..

I started to use ST10r165's and cr167's as a more powerful alternative to 51's , but the cygnal chip have made me think again(>=50 mips).. (alas no easy 9600 baud though.)
You'll have way enough ports , and using the crossbar you can decide the function of each pin in each port.