Patriots have legacy and pedigree on their side, which works well when the league is somewhat evolving at the same pace. But things can be altered when you simply switch philosophies and manage your assets properly, as the Falcons have done. The team rebuilt around Dan Quinn's expertise of a high-octane defence that hits hard and often. The schemes are unpredictable, and despite the overwhelming power of New England's O-line, I think Atlanta's speed will prevail overall if they can simply keep everything up-tempo. That could be a problem matched up against a heavy front line, but the Falcons' secondary is quick and adaptable, and has proven that while they will concede yards, they keep the points down.
Atlanta will need to hope that Alex Mack can stay in the game for Matt Ryan's comfort level to stay where it needs to be. He's coming off a great season, and needs to get off to a good start, but also make sure to finish well. Mack is key to stopping pressure, which New England doesn't really put up much of, ranking somewhere around 23rd in blitz attempts. Atlanta can contain the edges well, or at least buy some time for Devonte Freeman or Tevin Coleman to establish some kind of running attack and set up the play-action game. If they can get into that type of setup, the Falcons become an elite offense, and it bodes well for their hopes against a team that has done it before.
Some are doubters - I am a believer!