Post other possibilities and I will add them. It doesn't matter if they're long shots or totally crazy - if they have any validity, we'll put them on the list.
Bold text denotes they are being interviewed or have a strong likelihood of being interviewed. In no particular order:
Brian Billick
Bill Cowher
John Gruden (if fired)
Wade Phillips (if fired and if Bowlen can hire a coach he himself fired)
Eric Mangini
Rod Marinelli
Mike Martz
Jason Garrett
Kevin Gilbride
Jim Johnson
Romeo Crennell
Pete Carroll
Herm Edwards (if fired)
Marty Schottenheimer (as gm only - Bill Parcells role)
Mike Tice
Steve Mariucci
Steve Spagnuolo
Rex Ryan
Gary Kubiak (if fired)
Kyle Shanahan (oh god, that would make Shanahan's head explode)
Jeremy Bates
Josh McDaniels
Dennis Green
Jim Schwartz
Mike Leach
Bob Stoops
Dave McGinnis
Raheem Morris
Mike Heimerdinger
Karl Dorrell
Jim Harbaugh
Urban Meyer
Rich Dennison
more to come...