WikiTeam has just finished archiving all Wikimedia Commons files up to 2012 (and some more) on the Internet Archive: https://archive.org/details/wikimediacommons So far it's about 24 TB of archives and there are also a hundred torrents you can help seed, ranging from few hundred MB to over a TB, most around 400 GB. Everything is documented at https://meta.wikimedia.org/wiki/Mirroring_Wikimedia_project_XML_dumps#Media_tarballs and if you want here are some ideas to help WikiTeam with coding: https://code.google.com/p/wikiteam/issues/list.
Nemo