5-10 years maybe more. As soon as GPUs are fast enough to drive one. 1080 will remain a standard for a very long time, and has proven to be a much better choice in a typical living room. 4k has only proven useful in movie theaters due to the very large screens. Like always the TV will be first to get to this point. Games keep getting more demanding but maybe sooner than 5 years, but I really doubt that.