I think a min. of 50% of the Player with High Levels will leave PlaneShift 
From a developers point of view, I don't care if all of our players leave as long as the wipe was to improve the game. We'll always get more players. At the stage we're at, what matters is developers. Players matter more once we're feature complete (the basics anyway). 
As I said, eventually we'll get to the point where we'll have no choice but to wipe (selectively), so it's going to happen (more than once most likely, for different areas) in future.
Here we have a problem. If the developers don't care if all the players go, then I guess former players such has PSTruth will have more ammo and more supporters for giving 'balanced' opinions of PlaneShift. If you drive away players there will be a few who decide to get back at PlaneShift's development team by deterring possible new players.
Even though the players have not put half as much sweat and blood into the game as the developers have, they still have spent time and effort in the game, testing it for the developers. Testing their creation and reporting back on it. So a few happened to have max'd out a couple stats or skills, that doesn't necessarily make them powerlevellers. It just means that they rather walk the talk and talk the talk in their roleplaying. What I guess I'm saying is that there's two halves to this game and whether or not you agree with me, both have to be there for this game to continue on its current path.
If we wanted a cold-blooded reaction from the development team, we would play other games. What makes PlaneShift different, in my opinion, is that it has a human quality to it. The players interact with the development team and the development team interacts with the players (hopefully). By saying we're going to wipe the game regardless of what you think or what you say, its sending a negative vibe to the players saying well, we really like you, but your opinions aren't worth a dime to us. If that's so, why would we continue to play a game, where our opinions don't matter?