Scoble and Shel Israel make a good point about blogging - you can't force it:
He and I met the other day and he told me that he is hearing lots of companies thinking about integrating blogging into their marketing plans. You know, treating it as yet another marketing “chore” that teams need to do to be able to ship. He thought that idea is lame and will end in failure for those who approach blogs that way. I agree.
Blogging is writing, when you get right down to it, and you can't really force that. When your organization produces white papers, you probably have specific people who produce them. Sure, they get feedback from a variety of people in the organization, but those people don't each write a paragraph.
The same thing applies here. If you want effective blogging, it needs to come out as a natural voice. Forcing it on a team as part of their day to day job isn't going to result in a natural voice, and - if they are irritated by the mandate - then that irritation will shine through.