@Riot, have you ever considered adding more decision making when it comes to taking Baron?
So I was sitting in a Custom against a few bots getting fed so I could try an off-META build on Udyr (Mercs, TriForce, FH, Gunblade, SV, Rageblade) for fun, and then I tried Soloing Baron with it. While I was taking it I realized that minion waves in the side lanes were building up and getting pretty close to my turrets and I thought "geez I'd be screwed if there were actually Player-Controlled Enemy Champions".
This got me thinking - what if there was more decision making when it comes to taking Baron? Right now, it's a matter of, "Can we take Baron safely?" Yes - take Baron. No - continue playing until the answer is yes. After a team takes Baron, they can then play super offensively with a rather large statistical advantage. The only strategy left against a Baron'ed-up team is to play cautiously and wait it out, or hope they make a mistake.
This in turn got me thinking - should Baron be purely offensively tuned? Right now, there's no weakness to taking Baron. It's a power play with no strategical disadvantage. You take it and you dominate and snowball while you have it.
But what if a team with Baron who will undoubtedly want to group and teamfight was vulnerable to the anti-teamfight of tactics - splitpushing. What if while a team has baron, their structures become more vulnerable to attack?
Food for thought.
This will probably get a lot of hate from people who think Baron should be an advantage and nothing else. I'm just pointing out that it could be a strategy not a power-play. Baron should be to sieging what activating righteous glory/talisman is to starting a teamfight. If you get Baron for the sake of getting Baron, there should be some way to punish lack of execution by the team who got it.