Cam Cameron, I think is the obvious choice. Once the season is done, Tuna is going to hit that locker room hard, top to bottom. Cam seems to have lost his team, which is always a bad thing, but after this season, I think he'd have to go even if all 52 Dolphins started picketing for him to keep his job.
Tom Coughlin will probably go quickly, too, if the Giants lose in the first round again. He's gone anyway if there's a good coaching prospect that becomes available; the only reason the Giants didnt fire him after last year was they were hoping Cowher would be back in a year and just wanted Coughlin to keep the coaching seat warm for him.
The coaching carousel probably wont be too crowded this year, though...the other really bad teams like STL were all either injury plagued, so the coach gets a mulligan, or they have coaches who are there to rebuild the team, like OAK or KC, or they have coaches who have been successful enough in the past that one bad season wont put them on the hot seat, like DEN and CHI.
The only other two coaches I'd imagine are on the hot seat would be Billick in Baltimore, if he doesnt find himself a good name to take over offensive coordinating, and Nolan in SF, with the same hole to fill.