Grey Warden and possible King, Alistair, isn’t a playable party member in Dragon Age: Inquisition. Executive Producer of the Dragon Age franchise, Mark Darrah, announced this through a reply on twitter earlier this week.
.@TaylorW15000 not a party member. You’ll have to wait and see on the rest.
— Mark Darrah (@BioMarkDarrah) February 4, 2014
It is likely that Alistair, along with other previous party members, will make cameo appearances. Dragon Age 2 character Varric is already confirmed to return as a party member, so expect it to be similar to how Mass Effect 2 and 3 wove previous characters into the plot.
Dragon Age: Inquisition is expected to release onto PC, PS3, PS4, Xbox 360, and Xbox One in Q3 this year.