Well, I must apologize. I've finally found the way to make the deployment using Maven. The trick consists in:
a) using Maven 2.0.9 (the embedder was apparently not working)
b) using dav:
https://concordion.googlecode.com/svn/repos/releases in the distributionManagement section
c) including the username and password in settings.xml
My distributionManagement is now:
<distributionManagement>
<repository>
<id>concordion-releases</id>
<uniqueVersion>false</uniqueVersion>
<url>dav:
https://concordion.googlecode.com/svn/repos/releases</url>
</repository>
<snapshotRepository>
<id>concordion-snapshots</id>
<uniqueVersion>true</uniqueVersion>
<url>dav:
https://concordion.googlecode.com/svn/repos/snapshots</url>
</snapshotRepository>
</distributionManagement>
And in my settings.xml:
<settings>
<servers>
<server>
<id>concordion-releases</id>
<username>myusername</username>
<password>xyxyxyxyxyx</password>
</server>
</servers>
</settings>
I still have to polish an issue regarding an assembly and asap I'll provide you with the csv line to sync.
https://svn.apache.org/repos/asf/maven/repository-tools/trunk/src/bin/synchronize/m2-sync/sync.csv