Phillip Windley has some food for thought, ahead of a panel discussion:
What do you hope to accomplish within your organization with your blog? What positive and negative experiences have you had?
Are you encouraging members of your organization to blog? How? How many bloggers are there in your organization?
One of the chief uses of blogs in an IT organization is narrating your work. How valuable is it for you to narrate your work. How valuable is it for you to read what others are writing?
I know of one IT organization that uses a blog format for network outage notification (along with the accompanying RSS feed). What uses do you see for the blog format beyond an individual journal?