What was said is IF there was any kind of degradation it probably wont happen in this time you own the chip.
Just keep voltage at no more than 1.35v and temps at bay and don't worry about it.
Best case is you get 4.5Ghz 1.3-1.35v
Worst is 4.4gGhz 1.3-1.35v
And higher vcore isn't worth it IMO for an extra 100 Mhz if you're lucky.
If you're really worried about it get Performance Tuning Protection Plan from Intel its $35 for 5960x
you get one time replacement within the normal 3 years limited warrenty.
I got just because of reports of Mobo VRMs burning out an taking chip out with it.
http://click.intel.com/tuningplan/Edited by Minedune - 1/16/15 at 6:24am