I think the spying, counterspying and dirty tricks are widespread and the coaching fraternity is hesistant to make any of it public because they'll just be exposed as hypocrites.
Remember that playoff game (I think it was the 1997 playoff in Kansas City) where the Bronco offensive linemen had to be taken off the field and toweled down because they'd had a lubricant sprayed on their jersies to make it harder for defenders to grab them? Stunts like this probably happen a lot more than we know.
No, I don't think the NFL will lose market share or popularity because of this. The fans already know half the league is roided up and they don't care. They already know the players live out-of-control lifestyles and they don't care.
I'm sure Goodell would rather be dealing with this than dealing with refs in debt to the Mob or their record-breakers being the target of federal investigations.
I can't imagine this story will get to the bottom of the problems nor will the fans care particularly.