I knew the series would be brutal in its violence much like the original series, but this is really brutal. It's not gory, just brutal.
Foggy going down in the first few minutes of the first episode was totally unexpected and hit hard. Popped me upside the head.
As soon as he put on the mask, I knew White Tiger was going down, but I wasn't expecting the Punisher shirt. However, as someone else mentioned already, I have a feeling that wasn't Frank, but rather has to do with the tattoos a few of the police were sporting (the fact that John Bernthal wasn't in the credits at the end seems to confirm that suspicion), which leads me to believe he'll show up to take out the crooked cops who are stealing his persona.
Mostly, though, back to brutal, the calls of the coquis at the beach over the credits was more brutal than his death. That was just twisting the knife, big time.
I'm sure it's safe to assuming Fisk is going to fall from his self-appointed grace, and the above spoiler probably is the road that ruins him (assuming he's behind it makes the suspicion mentioned in the spoiler even stronger). I see his own pride and insistence that things be correct as he sees them being the thing that puts him right back to being afoul of the very law he wants to rule the city. That's probably a Captain Obvious statement, though...
I have a feeling the wife ordered the hit. She's still mad at Fisk for trying to be Mayor and he's not telling her what his plan really is. But, it could have been Fisk. Either way, I agree, this is the start of what brings him down.