I don't think 4 slots are likely and more TDP is certain when display resolution is pushed @ 4K or above and high refresh. 4K res at low refresh should allow efficiency to reign in the TDP quite a bit but who's gonna spend the money on one of these monsters and not push for higher res/refresh and max eye candy. Cooling will be a challenge but I expect fairly tight limits for power allotment will be in place to prevent Chernobyl type events. Just speculation at this point but we'll see soon enough. I'm hoping to be able to max out my 5K super HMD on a next gen gpu without it becoming an extra furnace for my office!