Just this year he's released the Annotated Sorcerer - a version where you have the original text + commentary on the facing page, most of it is clarification but there are a couple of very useful changes.
The biggest one is the addition of "starting statements" to start the campaign. The GM produce a statement of location/feel and a statement of how sorcery looks. Otherwise there's a few small changes to a couple of powers - notably removing stuff like exact range calculations for a few of them, "inherent" abilities to Demon Types do count towards it's total power, etc.
Otherwise it's mostly clarifications now that in 2013, he's got the language to describe what he was trying to do before stuff like "narration trading" or "scene framing" were really well described back in 2001. Although the rules changes are minor, the game advice about how to RUN Sorcerer in the annotated version is quite excellent.