For those who think length of game isn't a problem, I'd suggest it might not be so much length of games as lateness of games.
During the Front Office Q&A session at TwinsFest, I asked how concerned the Twins are about pace of games, and Dave St. Peter said the big problem is that the 7th, 8th, and 9th innings are supposed to be the most exciting innings, and on many weeknight games you look around the stands and half the fans have left before the game reaches its conclusion.
I don't think this is ADD or a lack of attention span; it's that people have to get home after a weeknight game. I live in St. Paul, but when I take the bus & light rail to and from a game that's gone til 10:45, I'm often getting home close to midnight. People driving from the exurbs or further are experiencing the same thing--and if you've got kids, there's no way you're staying til the game concludes. That's a problem.
The one thing that irks me is the sheer number of pitching changes that occur, on average, in major league baseball games. This is a fairly modern phenomenon and it's getting "worse" year after year. Baseball has made all kind rules over the years to make the game better. How about limiting the number of relief pitchers that can be used in a game? I hope the Commissioner thinks about it. It wasn't a "problem" that needed to addressed 30 years ago, but it needs to be addressed now.
I'm also curious about strategies to cut down on pitching changes; that holds much more appeal to me than a pitch clock (even if it is on the books, it just seems distracting for me as a fan--and impossible to implement with runners on base, when the pitcher can just throw over to 1st to buy more time). The three main strategies I've seen are:
1) Outright limiting the number of pitching changes (with adjustments for extra innings). To me, that feels difficult to implement in a way that both impacts the game and doesn't have a radical impact on bullpen management (though in many ways, maybe that's not a loss).
2) Requiring pitchers to pitch to at least 2 or at least 3 batters after entering a game. This one's intriguing to me, but also somewhat radical and could have some problems around the margins (injuries, rain delays, etc.).
3) Capping the number of players who are primarily pitchers on the roster. This one probably holds the most appeal for me--I'd think it would have the least dramatic impact on strategy while still offering strong encouragement to limit pitching changes. And it could give birth to some "go both ways"-style players, i.e. a Drew Butera who's your back-up catcher but steps in to pitch occasionally when the bullpen's worn down (though classifying these sorts of players could cause problems).