What we Know:
Warlords in deeper development than Cataclysm or Mists of Pandaria.
They have a faster release table for Expansions and Patches now.
Dragon soul patch lasted just shy of 11 months. ICC lasted a year but it had a content patch with a raid.
5.4 came out beginning of September.
Since there isn't going to be a Ruby Sanctum patch and this patch will NOT last longer than 10 months, Warlords of Draenor will be released not later than July 2014, but June is better.
Gonna save this for later and refer to it when it's officially released.