I was down there on Day 2 photographing demonstrators and police. This was Sunday, so the NYPD was able to block off Wall Street, the bull, areas near banks, etc. so disruptions by the demonstrators were minimal. An Anon told me they had been forced away from Battery Park and into Zuccotti Park the night before, but there didn't seem to be much tension between demonstrators and police at the time and some of the police seemed friendly with demonstrators. Demonstrators have made it clear time and time again that they are also fighting on behalf of NYPD officers.
From reports I've read through Twitter and elsewhere, some NYPD officers have shown at least some support for demonstrators but the "white shirt" commanding officers are the ones who usually instigate trouble. I can't verify this directly, but in many of the photos and videos I've seen of arrests and attacks on demonstrators, "white shirts" appear to have been directly involved. The now-infamous pepper spraying of penned in female demonstrators was done by a white shirt officer who also appears to have sprayed some of his officers as well.
I'm planning to head back to Zuccotti Park this week to get more photos, so I'll have a better idea of how much things have changed in the past week or so.