As a Pats fan, this is all disappointing.
A few thoughts:
(1) It didn't affect the outcome of the game....
(2) ... but that's not the point. The point is that it appears that the Pats did something to gain an edge, and pushed the boundaries of what is considered "fair".
(3) "Fair" in this context, as with other things related to the NFL, is a bit murky.
(4) If the Pats literally tampered with the balls, ie having a ball boy use a device to deflate the balls a bit, then it is clearly "unfair"
(5) If the Pats did something less direct to affect the balls, then it is not clear how "unfair" it is (I don't know the science of this, but some sort of initial underinflation to the balls, that are then slightly warmed (ie kept in a warm room for X hours), then taken into the cold... etc).
(6) Proving or showing evidence of either (4) or (5) is going to be difficult in any case. But, that doesn't mean that circumstantial evidence won't be overwhelmingly against the Pats in this case.
(7) The NFL is not a court of law, so the NFL doesn't need to "presume innocence until proven guilty" or anything like that. I believe the commissioner could simply say "we have enough evidence, the Pats lose a pick" or something like that. My guess is that is what happens, and that it happens soon. The NFL wants this over and done with before next Monday...