General NFL coverage is driven by surface-level story lines, which is why today's matchup between the 6-6 Buffalo Bills and the 5-7 Philadelphia Eagles has focused almost entirely on LeSean McCoy, Chip Kelly, and DeMarco Murray this week.
It will, indeed, be interesting to see how McCoy performs in his return to Philadelphia - but it's much more interesting when placed in the context of a Bills team that needs him to be at his best, and which could very well emerge as a serious AFC wild card contender with a win and a Cincinnati victory over Pittsburgh today. This is a huge game for McCoy, but it's a bigger one for the entire Bills organization.
Philadelphia has a lot on the line, too. Even though they're below .500, they're currently tied for first in the dreary NFC East, and could very well back into the playoffs with a division win if they can skirt past New York and Washington in the standings. The Eagles also have a unique approach to the game, particularly on offense, and many very good players (hello, Fletcher Cox). This game is nearly as big for the Eagles as it is for the Bills.
The McCoy-Kelly-Murray story line, then, is merely the icing on the cake that is an otherwise meaningful game between two playoff contenders in separate conferences. This is not a make-or-break game for either team, but a win would be huge nonetheless.