While testing continues and a delay could possibly change these dates, we are currently planning to start Season 3 on November 20 once the realms come back up from their weekly maintenance. This means that Season 2 will come to a close when the realms come down for maintenance on November 20. During that maintenance the final standings are taken and the end of season rewards are distributed.
The start date for Season 3 is purposefully planned to be one week later than the release of patch 2.3, which is currently scheduled for November 13. We will be closely monitoring the testing of the 2.3 patch, and if it looks like it won't make the November 13 date, we will announce a delay.
This confirms earlier news pulled from the WoW Taiwan site. Guess it's time to lay off the alts (at least until Tuesday) and get farming Sporeggar rep.