After a ton of speculation, a bit of denial, and a ton of testing we finally have our answer. The thermal interface material change made by Intel when it went from Sandy Bridge to Ivy Bridge is indeed the cause of the excessive temperatures we’ve observed while overclocking. The first accusation was made in late-April by Overclockers.com, however proving it wasn’t easy. The Japanese division of PC Watch somehow managed to remove the integrated heat spreader from a Core i7 3770k, along with the stock binding and grease. They then proceed to replace it with aftermarket alternatives, and the results speak for themselves.

Read more at:
Maximum PC | The Proof is in

Thanks for the link Shawn. I'm going to order my 3770K in a few week's time but I wonder if Intel will have anything to say about this before then