I noticed David's blog about the 3.0 Beta1 being available for download. However, the project download page http://www.jboss.org/jbossremoting/downloads/ seems to point to an incorrect URL for this download.
The link points to http://www.jboss.org/jbossremoting/downloads/jboss-remoting-3.0.0.Beta2.zip which does not exist. Notice that it mentions Beta2 in the URL. Infact, the download page shows the release name as Beta2.

I changed the URL manually to http://www.jboss.org/jbossremoting/downloads/jboss-remoting-3.0.0.Beta1.zip and was able to download the release.