As the intel heatsinks should be NIB, I wouldn't hesitate to use the intact TIM (Thermal Interface Material). However if you ever remove the new Intel heatsink afterwards, it's best to scrape all the TIM off and apply a nice even *thin* coat of thermal grease.Yes in fairness I had a layer of the pink bubble wrap around the board also but I wasn't sure if it was antistatic or not. I'll be taking it all apart tonight to clean off the included thermal compound. Did you use the included thermal compound on the new Intel heatsinks or did you use your own? I was planning on using the arctic silver I have from other builds.
FYI, I just received my 2nd natex shipment (2xCPU, S2600CP2J, 8x8GB Nanya RAM). I'd just mounted it in my second P4000M chassis, had ran through the BIOS/FRUSDR updates, and now starting in on a memtest. So far, so good.