The answer is: when someone else writes it - especially for internal organizational consumption.
For me, this is no longer a blog. Like a hamburger, this is something that has been distorted from it's original form by process: it becomes processed PR. Most leadership programs these days focus on soft skills including accountability, transparency, openness and reflexivity. This is the opposite - it's opaque and controlled. All human-ness is removed. And the author never receives the benefit of reflection, something required to put together their thoughts in a coherent way.
That's why I like social technology - it forces us to be open, reflective, to test our ideas, to bring ourselves back into organizations. There is no space for over-processing (and it's quite apparent if you get someone to post on your behalf). That leaves the only option for everyone is to get out there and practice your digital writing skills - do it yourself. Take time to consider and share your ideas and thoughts; and know that whatever the response - you will learn something.