Kvetch's post is basically a rehash of what Virisin has been trying to say all along, except she is more articulate, and hence the reason why she is a builder and Virisin isnt. Essentially, she has got it correct when she said we are converting the current 4d system into a proper full blown gaming system that involves a more complex and diverse set of combat.
Our aim is to make no two combats the same, even if you are killing the same mob. The skill trees has lots of side effects, as mentioned in the numerous posts in the other thread, and those benefits actually effect the economics of 4d. We have a great chance of fixing alot of inherent flaws in 4d with a pwipe, and if there was any other way, we would have chosen it.
Anything that costs gold, tokens, TPs should be wiped. Anything affecting the game should be wiped. RP gear can be reimbursed as long as it does meet these criteria. As I have said before, half assed measures in the past has led to the current situation today, and I do not want to repeat history. The problems with today's system is diverse, both of having crappy code that does not support the quality of the areas, and the economy. It does not make sense to have healers and potions out of reach of newbies, and yet they are basically useless for the experienced players (I am generalising here, I know you are using potions, but not to the extent that is a gold sink).
So if we had a pwipe without the myriad changes, then it becomes ineffectual. We are doing this not just because of the combat upgrade (skill/spell upgrade, class revamp, different type of prac system, etc), we are also targeting the problems with inflation, and designing a proper economy that will make 4d thrive. Hopefully, we might even end up having a player run economy!
So I am just adding to what Kvetch has said, her explanation is a perfect analogy of what we are trying to do - in fact, skill trees come from AD&D 3.0+.