Not as Worf or Dr Horrible, mind you. Although I live in hope that one day Worf will be forced to deliver Wonderflonium on the orders of Bad Horse. Maybe that'll be a DLC mission.
Volition's announced the full voice cast for Saints Row IV, and it's an interesting bunch, ranging from Nolan "I am every videogame voice ever" North, through to Neil Patrick Harris, Terry Crews and Rob Van Dam. Here's the full list, including all the voice choices for the President/Player role:
Keith David — As himself Danielle Nicolet — Shaundi Jennifer Jules Hart — Shaundi #2 Natalie Lander — Kinzie Kensington Terry Crews — Benjamin King JB Blanc — Zinyak/Phillipe Loren Michael Dorn — Maero Neil Patrick Harris — DJ Veteran Child Yuri Lowenthal — Matt Miller Arif Kinchen — Pierce Washington Tim Thomerson — Cyrus Temple Mike Carlucci — Zach Rob Van Dam — Bobby Rebecca Riedy — Asha Odekar Andrew Bowen — Josh Birk/NyteBlayde Michael Yurchak — CID TC Carson — Big Tony Ursula Taherian — Tanya Ogie Banks — Warren Williams
The President: Nolan North — The Player Troy Baker — The Player Laura Bailey –The Player Robin Atkin Downes — The Player Diane Michelle — The Player Kenn Michael — The Player Sumalee Montano — The Player
Saints Row IV voice actors revealed [Destructoid]