Faction change when blizz??

Im tired of playing ally and i want to know when the faction change will release. I understand that it can come at any time, due to the service doesnt need a patch. It will just be there optional. But blizz could you please tell us when or atleast when you think the service will be here?

Also wondering lets say im exalted with all the alliance cities, will i be the same with the horde cities if i go horde?

And what do you guys think, will the service be here soon? Or will we have to wait months?