Yes, PvP detection was removed.
I don't really understand why, beyond newbies bumping into eachother. (This could have been taken care of by simply removing the pop-up functionality of PvP.)
Yes, push-based (you know... PvP) griefing has already increased.
No, abuse reports probably haven't, because we don't have anything to file.
I need to mention that:
Babbage Linden's "wear a script!" solution is not a solution.
We have folks wearing scripts to make them fly, to keep them from being bumped, to change their pose, to make sparklies erupt, and now to do something that the system used to do for them - tell them who just blasted them.
They usually wear these all at once.
They do take up lots of resources.
I just don't know if this is a move towards what you folks call "community policing" or what, but it isn't a reflection of reality. "On the ground", in SL, you can't walk up to "griefer A's" buddies and have a talk with them, getting them to give up his name so you can AR him.
The griefers KNOW that PvP reporting is gone. They're VERY happy about it. And exercising their newfound freedom.
I also suspect abuse reports are down, because few people will file an AR simply stating, "I was standing there, and I went flying." They know it won't go anywhere.