On the TrekBBS Keith R.A. DeCandido has revealed a little detail on his new character for the Destiny follow-up novel A Singular Destiny - in the form of a short excerpt, in which Captain Dax first meets Sonek Pran:
Seconds later, a sparkle of lights coalesced into a humanoid form. A large canvas bag was slung over his left shoulder. He had a drooping white mustache and long white hair, framing a round, pleasant face. He wore simple civilian clothing: a purple shirt, black vest, black pants, brown boots. The rather unruly head of hair was yoked back into a ponytail, revealing tapered ears that suggested Vulcanoid ancestry. He also had the rhinal ridges of a Bajoran, albeit fainter than usual, and the black eyes of a Betazoid. That's gotta be an entertaining family tree, Dax thought as she stepped forward
"Professor Pran, I presume?"
The grin he let loose with was completely human. In all three hundred and sixty-three years of life in nine hosts, the Dax symbiont had never encountered a species that grinned quite the way humans did.
Go forth and have a chit-chat about the fellow, here.