There are an awful lot of loose threads around the tauren right now. The Grimtotem are scattered, making temporary pacts with the Alliance in Stonetalon, besieging the night elves in Feralas, and their greatest leader was last seen claiming an artifact of elemental power. In the wake of Cairne's death, Baine Bloodhoof chose to allow Garrosh to rule uncontested - but that position clearly changed over time, and Baine led tauren troops to the support of Vol'jin's rebellion against the Warchief, rather than simply challenging him as his father did. Ironically, this choice shows a certain political maturity - recognizing that trial by personal combat might not be the best means to effect regime change in the Horde - while it also shows a bit of a break with the old ways of both the Horde, and the tauren people.
Baine's father Cairne chose to live, and die, by the older ways of ritual and honor. Betrayed by Magatha, he died from poison on Garrosh Hellscream's axe and with him seems to have died the last vestiges of the tauren ways of the past. Baine led an expulsion of those Grimtotem that would not swear allegiance to him over Magatha that culminated in a battle against their last leaders in Mulgore, and at the end of that battle, Baine ruled the shu'halo as undisputed chieftain of all. But in doing so, he also led his people into their last break with the past, and following the defeat of Garrosh and the ascension of Vol'jin to the seat of power as Warchief, one must ask - what role do the tauren fill in the Horde to come, and where will Baine's current choices lead them in the future?