We had some discussion of Maudlin's paper on the everything-list in 1999. I summarized the paper at http://www.escribe.com/science/theory/m898.html . Subsequent discussion under the thread title "implementation" followed up; I will point to my posting at http://www.escribe.com/science/theory/m962.html regarding Bruno's version of Maudlin's result.
I suggested a flaw in Maudlin's argument at http://www.escribe.com/science/theory/m1010.html with followup http://www.escribe.com/science/theory/m1015.html . In a nutshell, my point was that Maudlin fails to show that physical supervenience (that is, the principle that whether a system is conscious or not depends solely on the physical activity of the system) is inconsistent with computationalism. What he does show is that you can change the computation implemented by a system without altering it physically (by some definition). But his desired conclusion does not follow logically, because it is possible that the new computation is also conscious. (In fact, I argued that the new computation is very plausibly conscious, but that doesn't even matter, because it is sufficient to consider that it might be, in order to see that Maudlin's argument doesn't go through. To repair his argument it would be necessary to prove that the altered computation is unconscious.) You can follow the thread and date index links off the messages above to see much more discussion of the issue of implementation. Hal Finney