There are no easy answers to this. Baseball will work on cutting a minute or two off the times of games. But starting times, especially for the World Series, won't change drastically. That's hard enough. The 8 p.m. ET start time for Monday Night Football a couple years back didn't work, and instant replay seems to have lengthened pro football games.
Nothing there seems likely to change.
So we're stuck with late nights and early mornings and advertisers dictating when we watch. Of course, we could always not watch. Which, if you look at the ratings for the Series and MNF and the Olympics, is looking like a more viable alternative to many. But that's no option for the millions of true sports fiends out there, those who would rather watch sports on TV than watch anything else. There are no answers at all for those people.