I have pushed TeXLive 2013 packages to [testing].
The main difference with the 2012 packages is that /etc/texmf files are now in texlive-core rather than texlive-bin.
The texlive-bin package now contains almost only binaries, and texlive-core contains all basic data files including the ones in /etc/texmf.
Feel free to report any issues you encounter.
If you have an existing installation, the upgrade might install new versions of /etc/texmf/ files as *.pacnew. It is unlikely that things work properly if you don't handle the pacnew files unless you realy know what you are doing.
If pacnew files appear (notably texmf.cnf and fmtutil.cnf), and the installation reports a failure in regenerating formats (which you will know by not being able to use an engine), you will need to handle the pacnew files, and run "fmtutil-sys --all" by hand.
If this situation reaches a high level of absurdity, and if possible considering pacman's behaviour, new packages not behaving like this might be built later before going to [extra].