I mean, do you really think shutting down the PM's is going to stop what you guys see as being a huge problem?
The other unofficial forum doesn't look like it's going to flame out and die anytime soon. Most of the "cheaters" already use that place or have everyone's IM contacts. Newbies are going to notice that 2/3 to 3/4 of the players have decided that they want to share information freely, and while some newbs may latch onto the minority's "Shut the fuck up about the happy boots quest" mindset unless you ban people from giving out email and IM on this site the rest will easily get what they want.
I know none of you like it, but the genie is out of the bottle, and I don't think it's going to be as easy to shove it back in this time.