1) Fewer hitters. Match two American League hitters and two National League hitters. Round one. Match winners, round two. You wind up with three "winners:" League, most home runs total, match play winner. Might be really fun to form a third match -- two combatants from another sport or occupation. Winner meets the baseball winner in a final round. From the looks of things in the celebrity softball game, Nelly might be a competitor.
2) Each hitter gets three outs per inning. Game lasts five innings. This way a hitter can't get into a groove. The results are more realistic. The competition is more dramatic.
3) Call strikes. Again, this is more realistic. The side benefit is it will speed up the contest.
4) Ban children from the field.
5) Eliminate the current trio of announcers. They are fingernails on a blackboard. Replace them with one good play-by-play man -- one who understands the value of silence. Bob Uecker would be my nominee.
6) X-ray bats for cork. Or, not.