Not all of these keys need to be addressed to win and many of them won't.
About that defense...
Move on from Ihedigbo at safety.
After further review he had a worse game than I thought. He's still an improvement over Sergio Brown but that's not saying much. Nate Jones doesn't appear much better if at all. With Patrick Chung missing practice again, we may be stuck with Ihedigbo. Matthew Slater can hopefully build off of his two games at safety but still I dread the sight of Ihedigbo in coverage almost as much as I dread the sight of #31.
McCoutry needs to build off of his performance.
Assuming he didn't reinjure himself, McCourty had an inconsistent game. Which is good. Throughout the year he was consistently bad but he had some nice flashes towards the end. He needs to build off of that if the Pats are to have a chance. If he and Arrington both have a good game together....
Vince Wilfork and Andre Carter need help.
These two had a good game against Washington despite the 15-yard penalties they both accumulated(with Carter's for some reason costing a wouldbe McCourty interception) and all of the yardage the Redskins run game managed to get. But they need help, especially a mile-high. Kyle Love is an excellent rotating DT, but I'm not convinced that "Mini-V" is starting-quality. He may function better as Vince Wilfork's backup in this game with all that thin-air. As for Andre, he is going to need help in setting the opposite-edge against the Denver run game and pass game. Maybe more Brandon Deaderick?
About that offense...
Would the 2nd WR please step up?
Whether it be Deion Branch, Chad Ochocinco, Tiquan Underwood, or whoever we just signed, Brady could use more than a single wideout to go with a pair of Tight-Ends. What if Wes Welker or Rob Gronkowski are drawing double-coverage? TE/WR Aaron Hernandez(formerly Tebow's favorite target) has looked much better than he did immediately after his injury earlier in the season, but sometimes the TEs have their timing mangled by opposing defenses.
The Center needs to hold.
Actually, the Left-Guard/Center area needs to firm up. Wendell looked more solid at Center than McDonald(who got most of the reps vs. Washington), but maybe I'm missing something. LG Logan Mankins hasn't been himself all season. Pressure up the middle is the kind most likely to kill dreams of playoff glory and this game is going to have a playoff atmosphere to it.
Establish a run-game.
Don't let Tebow control the time of possession.