With three games left on the schedule, the 8-5 Lions currently control their own fate for the playoffs. If the playoffs started tomorrow, the Lions would be in (with or without the Broncos' stunning comeback win over the Bears).
Of course, the playoffs don't start tomorrow, so we have to hypothesize how this might play out over the final few weeks. That being the case, ESPN's playoff machine is our friend.
The teams who haven't already clinched and are still alive for a playoff spot are New York*, Atlanta*, Detroit*, Chicago, Dallas, Arizona, Seattle, and Philadelphia (* denoting teams who are in right now).
For the Lions to make it at 9-7, they'll first need a loss from both the Seahawks and Cardinals. If either of those two teams win out and the Lions can only win one of three to finish the season, they would have the tie-breaker over Detroit. Luckily, one will knock out the other in Week 17, so the Lions just have to hope the winner of Week 17 loses one before that, too. At 9-7, and a loss to Green Bay, the Lions would get in over a 9-7 Bears, too, unless one of the Bears wins comes against the Packers.
Of course, that's all moot if the Lions can win two games. If they take care of two, say the Raiders next week and the Chargers on Christmas Eve, they'd only have to be worried about the Bears winning out, which is probably not going to happen considering they play the Packers, and I don't see the Packers losing at all.
Overall, you have to like the Lions chances right now...
Here are the remaining schedules for the teams still alive:
New York Giants (Washington, @New York Jets, Dallas)
Atlanta (Jacksonville, @New Orleans, Tampa Bay)
Detroit (@Oakland, San Diego, @Green Bay)
Chicago (Seattle, @Green Bay, @Minnesota)
Dallas (@Tampa Bay, Philadelphia, @New York Giants)
Arizona (Cleveland, @Cincinnati, Seattle)
Seattle (St. Louis, @Chicago, San Francisco, @Arizona)
Philadelphia (New York Jets, @Dallas, Washington)