Odamex has officially been upgraded to 0.5.4. From the Odamex website:
Odamex 0.5.4 is a rather hefty release that will ultimately serve to bridge the gap between the 0.5 series and 0.6. Along with the usual bug fixes, it features a number of experimental features expected to be complete for the 0.6 release...The most notable of the new features found in Odamex 0.5.4 are both the inclusion of unlagged support and early net demo support, both of which have been a long time coming. These features are both currently in experimental stages, so while we encourage you to give them a try, we also encourage you to report any issues or bugs that you run across while using them so that the Odamex team can do its best to stamp out these issues going into our next major version.
There are many additional changes for both players and server administrators in Odamex 0.5.4 that you can read about in more detail on the release page, SVN changelog, or the official release statement.