Brain in a jar, anyone? Science fiction gets closer and closer to the mundane, although I still don't have that jetpack Popular Science promised me.
I wonder, though, if "computation" is all that goes on. Heidegger divides calculation from contemplation quite sharply, and I'm not sure he's not on to something. It seems that there's something quite different going on when I, say, play chess or ping-pong, compared to when I'm reading philosophy. I've yet to be convinced that my more abstract maunderings can be reduced to ones and zeros.
Of course, better men than I have been and are so convinced. Poincaré in particular felt that the mental process (of creating new mathematical theorems) was one of trial and error; that one simply shook the pieces until they fell into place. It still leaves the question of more abstract thought (for example, questioning the thinghood of a mathematical concept doesn't seem to be answered readily by guess & check), and that of how one selects the "pieces" to shake in the first place, since Poincaré considers that the most time-consuming part of the work. It's also interesting to note that he claims that all his discoveries came when he was not specifically thinking about the problem. He would work on it until he reached a limit, and then allow some other part of his mind to deal with it. He often woke up with the solution fully formed in his mind. Shades of Athene.