well for the Royals games I do watch, i'd like the average of those games to be 2:28. And I easily watch parts or all of at least 100 of the 162 games, so that's a lot.
But I would love to start watching the playoffs and world series again when they get finished cleaning up the game lengths.
I'd also like for my young son to eventually enjoy watching baseball, but unless it's faster I know he'll gravitate like the other teens towards things that are fast and end quickly like MMA or X-games or crap like that.
You should start watching soccer. Barring a very major injury, the game is done, start-to-finish, in like 1:55. The only time it goes longer is if there's extra time, which means that it's a tie in a very important game (thus you don't mind watching a little more, like OT in playoff hockey) - and even then it'll be ~2:40 tops. Really doesn't get much better in terms of sports appointment-viewing.
I really like the idea of soccer.
I love how they keep their games tidy... sadly at the expense of a result, which seems crappy.
To me solving soccer seems so simple, just make it easier to score so the average game can have like 5-6 goals instead of 2-3... a 20% increase in the size of the goal should take care of this without altering any other rule.