I just got the Asus P5K-E Wifi today and haven't really gotten to overclocking yet!
There are numerous reports around the net saying that this is THE board for quad core overclocking, but we'll see soon enough if that holds true! Can't wait to push for 4Ghz!!
(not going to come close due to a very high VID
Had some problems getting the drivers for the chipset installed due to me running server 2008, but it seems to be running fine now.
28c idle temp on all four cores!
EDIT: Here's a guide on how to do the pencil mod for the P5K-E Wifi: http://www.overclock.net/motherboard...-e-pencil.html
Did it a few seconds ago and it was very very easy and my core voltage is now stable!
Currently running at 380x9.0(3400Mhz) with 1.45V set in Bios and 1.4325 in Windows(some drop there but it's rock stable!).