About a month ago, Flounder left us this hint on the Pathfinder dev blog.
While this is subject to change, we plan on opening up with a series of five scenarios that explore some events that befall Valeros (he does have an interesting backstory) and culminate in unique rewards and a new character added to the roster.
Who that character is has been currently narrowed down to one of two choices but they will be coming from the Fighter Class Deck and it isn't another version of Valeros, so that's your hint.
That leaves us the following options:
Flenta - Not technically a sorcerer, this female halfling has a flair for the arcane arts, even if it is all just slight-of-hand
Tontelizi - "Retired" from a shady past, this gnome is unstoppable with his polearm and a few allies
Vika - A half-elf who quit her job as a blacksmith to try smashing new and exciting things with her trusty hammer