1) Brandon Browner returning to play against Seattle for the first time since he left the team in the offseason. Along this storyline, Browner said Monday he'd do anything to win the SB including harm Richard Sherman. He was quoted saying, "I'm going to tell my teammates, 'Go hit that elbow, go hit that shoulder,' Try to break it if you can." (Source: http://www.sbnation.com/nfl/2015/1/26/7916165/super-bowl-xlix-2015-richard-sherman-brandon-browner-break-arm)
2) Tom Brady's legacy. People will always remember he won 3 Super Bowls early in his career, but will they also remember he lost his last 3 chances too? If the Patriots lose, it doesn't mean Brady doesn't deserve to be in the Hall of Fame, it just brings into question how people will truly remember him. Pats fans will remember the wins over the losses, but his doubters/haters will focus on the three straight losses (IF they lose). If they win, it will certainly help his case for Greatest QB of All-Time and it will silence people like me bringing up if his "legacy."
3) The NFL vs. Marshawn Lynch. The NFL seems more interested in fining or disciplining Lynch than anything. Now, I'm not a Seahawks fan, so I don't really have a feeling one way or another, but I think the NFL picks on him a little bit. I have changed my stance on making players talk, I still think they should, but fining/forcing a guy to talk is making it more of a spectacle than it should be. As lame of a storyline as I think it is, the NFL and Lynch have a mini back and forth going which is fun to watch as a fan.