When upgrading to filesystem-2013.05-2.2 there might be a conflict with /etc/parabola-release.
Install the package as follows:
rm /etc/parabola-release && pacman -S filesystem
The reason for the conflict is that the file was formerly an orphan generated by the post_install script of the lsb-release package. Now the parabola-releasefile is owned by filesystem and it will solve problems for other packages like lsb-release which use it. We have also added a file called arch-release which is a symlink to /etc/parabola-release, for compatibility with Arch packages.