I just got back from Sprint Corporate Store. I showed them the white spots(Hot Spots) on my EVO 4G, just like everyone else has, and to my amazement, they knew of this problem and has a fix for it. They made a ticket out for me, took my phone, and in 2 hours my phone was fixed. Sprint Corporate Stores have replacement screens right from the factory, brand new from HTC. She replaced the problematic screen with the new screen. Also the earpiece had to be replaced because it is attached to the old screen. The new screen looks gorgeous and vibrant. My EVO looks brand new again. There is no charge for this at all and is covered under original warranty, so don't be scared to take it into the Sprint Corporate store to have it fixed. You get to keep your phone, no refurb, and get it looking brand new too.
By the way, the screen looks a lot brighter than the one I had. I have the original EVO, day one, hardware 2.
Just thought I would let you know it is o.k. to go to Sprint and get it fixed.