cottewmi:
the arduino would be , in a practical sense, incapable of having a graphical user interface and on board programming abiltiy, as well as limiting the use of wireless internet capabilities.
I'm not so sure about that. You would need to define what you want. A Mega2560 has a reasonable amount of RAM, program memory, quite a few interface pins etc. You could connect a LCD using I2C (using only 2 wires plus power and ground).
And what will the raspberry be doing? Acting as a counterweight?
And doing a fantastic job, no doubt.