When will wow patch 3.4 be out

The next patch will be 3.3.5, and features the Ruby Sanctum. There's no telling when patch 3.4 will come, or if there will ever be one.

Patch number 3.9 (pre-Cataclysm Events) will feature the retaking of the Echo Isles and Gnomeregan, and is planned to appear just before Cataclysm.

If no other events are planned, it is possible Blizzard will decide to jump straight from 3.3.5 to 3.9.