Any guesses on the reputation factions that we might see in WoD? My guess is that we'll see quite a lot of faction specific ones as they seem to be moving towards a more faction segregated experience compared to other expansions. Plus there doesn't seem to be much opportunity for many neutral factions. My guesses:
Horde:
> Main Horde expedition.
> Frostwolf Clan.
> Blood Knights (We know they'll be appearing.).
> Farseers.
> Blackrock Clan. In 6.1, the remnants of the Blackrock Clan lead by Orgrim Doomhammer.
Alliance:
> Main Alliance expedition.
> Karabor.
> Blood Knight counterpart. Maybe Sentinels?
> Draenei Archivists. These and the Farseers will be the Lorewalkers of the expansion.
Neutral:
> Arrakoa (as the Klaxxi of this expansion - The followers of Anzu helping us fight those Arrakoa who have turned towards the Old Gods.).
> Sporegar perhaps?
> Shado-pan Expedition? No word on the Shado-pan but it makes sense for them to send some forces after Garrosh.
> Gul'dan. Supposedly acting as an ally. I expect he'll be this expansions Black Prince, helping us on our Legendary quest.