Link to the Horde ending. Thrall and the other Horde leaders throw their support behind Vol'jin. So yeah, he's Warchief alright.
Being an Alliance player, I really have nothing for or against Vol'jin. Seems like it may be interesting though.
From the Alliance standpoint, I was quite satisfied. You have to keep in mind that it would be impossible from a gameplay standpoint for the Alliance to do anything more than what was portrayed in the cinematic and what was alluded to in the future in the following quest text from Varian. The King, standing *in fucking Orgrimmar* tells the new Warchief, with the other leaders present that if this shit hits the fan again, they will be utterly destroyed. And not a damn one of them did anything other than stare blankly as he grabbed his sword and left them to rebuild their faction.
Couple that with the fact that even from a storytelling standpoint, why would the Alliance want Orgrimmar, Thunderbluff, or any of the Kalimdor capitols? What would we do with them, install indoor plumbing? They would be more trouble than they're worth and Varian was absolutely right in saying it would cause too many casualties. He seems to be making the smart play, heading back to Eastern Kingdoms, re-establishing an Alliance presence in Theramore, and focusing on the Horde race that *is* a genuine threat still, and *does* have things that the Alliance wants, The Forsaken. What better than for this new "proactive" Alliance to capitalize on it's current position than to retake Gilnaeas? And no, I don't think for a second we'll "reclaim Lordaeron" so let's not even go there. Gilnaeas is good enough, as it's an expansion of a Horde race at the moment, not one of their capitals. So the Alliance can take it, gameplay balance is unaffected, and the Alliance gets to feel badass for a bit and maybe get some good storytelling especially when you consider Jana seems to have a permanent case of the Mondays.