Striking out from the Damocles Gulf comes the newest supplement for Warhammer 40k, Farsight!
Clocking in at about 110 pages (like the Iyanden supplement), this book again features about only two pages of “must have” 40k relevant rules.
Details have been popping up all over the web on codex specifics.
http://www.belloflostsouls.net/2013/07/breaking-farsight-enclaves-arrive.html
http://www.lounge.belloflostsouls.net/showthread.php?34465-Farsight-Supplement-Rules
and http://greenblowfly.blogspot.com/2013/07/confirmed-farsight-enclave-rules.html