It is a bit confusing that http://dumps.wikimedia.org/enwiki/20121001/enwiki-20121001-md5sums.txt has newer hash values that aren't in http://dumps.wikimedia.org/enwiki/latest/enwiki-latest-md5sums.txt. I'm guessing that the "latest" md5sums files get updated only at the end of a cycle when all dumps for the month have been completed? (In other words, the idea is that the "latest" directory contains backups that have been *completed*, and the md5sums file isn't complete until *all of the other backups* which it is going to reference are complete.) I was expecting the "latest" md5sums file to have "rolling" content matching the rolling content of the "latest" directory itself. If the latter is possible without too great of administrative hassle, it could be a nice feature. Otherwise, it would seem that "latest-md5sums" is almost always outdated relative to the other files in "latest".
-Zach