My idea has always been 6 innings of 5 outs per. It would incentivize small ball/putting the ball in play more, because you could actually string some runs together the old-fashioned way. And then it also gets rid of a lot (well, 1/3) of those annoying field changes. Obviously there is ad revenue to be had in those times, but half the Pirates' commercials seem to be about the Pirates anyway. I'm sure that applies to most teams for the games on local programming.
It will obviously never happen, but the rules are so arbitrary anyway that I don't see why not.
Every sport has evolved into a game of mosts. NFL is all about the shots downfield. Baseball is all about homeruns. Basketball is largely 3-pointers. It kind of feels like when WWF went from these well-choreographed, believable matches to just 15 minutes of highlight reel stuff every time. It's cool for a while, but then it loses its luster.