Most Linux distro's don't even bother to regularly update Calibre in their repository. Someone may take a look at it every two or three months or so, because Calibre is developed way too fast. Before the maintainers get the package tested and ready, the next version is already out.
Ubuntu just reached the 1.0 version:
https://apps.ubuntu.com/cat/applications/saucy/calibre/
SUSE still has 0.9 versions:
http://software.opensuse.org/package/calibre
Debian Stable (Wheezy) is only at 0.8 (and they won't update it in stable; you would need to get it from backports if it's there, or pull it from Testing, Unstable or Experimental)
http://packages.debian.org/wheezy/calibre