most media will be made in 1080p, but gaming resolutions will never stop. 1440p is increasingly becoming popular and until the next gen hdmi standard comes out, 4k at 60hz or higher will become a reality for some.
Who knows, but considering that there are still many stations and channels that don't broadcast in HD, I wouldn't expect 1080p to go *out* any reasonable time soon. If it's taken this long for 1080p to be adopted as little as it has, how much longer before 4k hits even that amount? If you are talking Pc gaming, 1440p pushes current graphics cards enough as it is. Crysis 3 at 4k is damn near impossible for anything other than triple or quad SLI on great cards(770+).