It seems that ubuntu raring 13.04 was released with a packaging problem in maven. I upgraded my home computer desktop quantal 12.10 to 13.04 raring and other some regular issues, which I usually solve by apt-get -f install, I got an error while installing maven. It seems that maven depends on both libwagon-java and libwagon2-java and both contain the same jar file. dpkg then will issue an error and stop.
By doing some search I found a page on launchpage with the error report: https://bugs.launchpad.net/ubuntu/+source/wagon2/+bug/1171056
I forced the installation of libwagon2 using dpkg -i –force-all /var…. and it worked. However, I know that now when one of those two packages gets removed the jar will be removed as well, and then I will need to purge then package then re-install it.