If I were going to promote some new characters, I'd start with Joanna Blueheart. This lady is about as close as we've gotten to a classic Alliance leader since the start of WoW, really. She doesn't sugarcoat the Horde's crimes. They are dastardly, and they have caused us loss, and that loss should never be marginalized or discounted. But at the same time, we are Alliance. That means we are honorable, and just, and noble. We don't fight wars for vengeance; we fight them to bring justice and peace and to defend our homes. We are gracious in victory, and we honor our fallen. That type of balance of wrath and nobility is something that the Alliance could really use right now.
I also think I'd do something with Grand Admiral Jes-Tereth. Technically, she's a pretty blank slate, so that might be cheating, but I have had a crush on her for years, I won't lie. The Alliance's naval power has sort of sat on the back burner for years, but it used to be a point of pride, and with Kul Tiras possibly entering back on the scene, it could be showcased all over again. A tough, no- nonsense seadog with the mind of a tactical genius, Jes-Tereth could organize assaults against the Forsaken, the Horde on Pandaria, and against all other Alliance enemies with a brutal precision, as both sea and airships bomb Horde military targets to fine dust. Also, Lieutenant General Andorov is a member of the 7th Legion now, and they love each other and have beautiful children.
Of course, there are many other players that could see promotion if given the chance, I'm sure. If you could promote one or two small players to a higher position in WoW lore, who would they be and what would they do?