A brief history of the Week 17 flex game is helpful in figuring out what match-ups are likely: It was instituted in 2010, in large part because of what happened in 2009. The Jets needed to beat the Bengals to get the final AFC spot, but the Bengals were locked into the 3 seed. So they rested their starters and put in a vanilla game plan, in large part because they knew there was a good chance they'd be facing the Jets the following week. (They did, and they lost anyway).
The league hated having one team roll over in its final regular-season primetime game, so they instituted new rules. All Week 17 games would be divisional match-ups, and the league would decide which game to flex into Sunday night, with CBS and Fox having no right to reserve any games. The main criterion for that game would be one in which both teams have something to play for, regardless of any other results from earlier in the day.
In 2010, the Sunday night game was Seattle-St. Louis, even though the match-up was less than ideal. In 2011-13, it was an NFC East match-up featuring the Cowboys: vs NYG in 2011, Washington in 2012, and Philly in 2013. (In 2013, GB-Chicago was also an elimination game). As mentioned, last year Carolina-Atlanta was an elimination game, but the league went with Pitt-Cinci instead, partly because it was a more attractive match-up and partly because they had stolen an NFC game from Fox for four straight years and figured they should balance it out with one from CBS.
Given all of that, what Week 17 games are likely to meet that scenario? First of all, you can rule out any game involving an already-eliminated team like Buffalo or Dallas, no matter how big of a draw they might be. The NFL really doesn't want teams phoning it in in primetime. However, for the first time since they implemented the rules, it is exceedingly unlikely that there will be any pure elimination games, where the winner makes the playoffs and the loser is out. The only scenario would be if the Texans and Colts lose next week and the Jags win; then the Week 17 Texans-Jags game would be win or go home (and the NFL would be super bummed. Not only would it be two low-profile franchises with sub-.500 records, but the Texans are likely to be rolling out Brandon Weeden at QB).
So what else? The two divisions where there could be a close race (AFC North/West), the two competitive teams don't play each other Week 17. Seahawks-Cardinals is a great match-up, but both teams are likely to not only have clinched playoff spots, but to be locked into their playoff positions. And I can't see either NFC East match-up making it. If Washington wins next week, they clinch. If they lose, then you have interdependent results between WAS-DAL and NYG-PHI, which is exactly what the NFL wants to avoid (although I think you might see both games flexed to 4 p.m.)
So that leaves two possibilities: In any Week 16 scenario other than Packers win, Vikes lose, their Week 17 match-up will be for the division, though both teams will have already made the playoffs. Alternatively, they could show Panthers going for 16-0 vs. TB (and you better believe both teams would be strongly encouraged to go all out in that case).
The nightmare scenario for the NFL: Texans/Washington/GB all clinch next week, Panthers lose shot at 16-0. No idea what they'd do in that case.
If Philly beats Washington, Washington will no longer control their own fate.
