WotC's site has a very detailed list, including all D&D and d20 Modern stuff, as well as novels, miniatures, etc. They're certainly in a much better position to do that than I am. My suggestion would be to go to their catalogue on their site and bookmark it for reference.
Yep, that is true for what is in the catalog. But, didn't this site used to also track those things on Amazon or elsewhere that weren't yet in the on-line catalog? No huge deal, it just seems like it would be nice to have that information somewhere.