Evan William's recent update on what he's learned while building Medium really struck a chord. But, his concept of "communication costs" was the key insight. Change management is always tough work. Duh, right? But, it's especially tough when you are a) making up new processes and outputs as you go and b) have a lot of people who are emotionally and proffessionally invested in it. The highest cost? The communication. From simple information ("here's what's happening now") to strategic alignment ("here's what we're going to do and why") to motivation ("Here's why you should be fired up about where we're going") to managing the emotions and expections and crisis, the communications are the hardest part. 

And, of course, the larger the stakeholder set, the harder this all becomes. 

Reason #2429471 to keep your teams smaller, and teh scope of your projects tighter.