As discussed earlier today on Twitter, PvP Designer Brian Holinka responded to an inquiry by saying there may indeed be a chance for an additional PvP season before Warlords of Draenor
comes out sometime next year.
Speculation on what "if we feel like we need it" means aside (no points for "if WoD
is longer in development than expected"), I'm sure another season would be a welcome opportunity for those PvPers looking for one more chance for their shot at earning their moment of PvP glory. At least before we all have to re-learn our classes again!