not yet tarnished per se, but as a poster above said...it is embarassing. especially for what is perceived to be the class franchise of the sport.
i believe i read that the violation is not that they did it in the first place, as most teams do the same things...but that they used a recording device like a camera to do it. ie, they can have a guy there monitoring signals, they just can't do it with videotape. from the articles i've read, that seems to be the specific violation that Goodell's investigating.
in any case, i don't think we'll have a much better handle on things until the season plays out. imagine the Pats finishing the season like 6-10 or 5-11 or something and suddenly people's questions will multiply. but...if they more or less win out and make a stand in the playoffs, people might forget.
people calling for a forfeit of the Jets game or barring them from the playoffs is just stupid. there is absolutely no precedent of that happening outside of collegiate athletics and it will end up being lawsuit city i bet if that happens. they'll get fined and lose some draft picks, possibly first round. that's all.
regardless, it has put some extra drama into the season.