As you might already know Shel Israel's and Robert Scoble's business blogging book is being built on The Red Couch.
In a post on March 9th, Robert Scoble shares his lessons for Corporate Blogging in "Dave Sifry and Niall Kennedy in lesson on corporate blogging".
(Just to remind you, he offers you to partizipate in this book, he wants your help, to make a "better" book on the subjects.)
I would prefer to call his lessons "constrains". They might keep you (and him) out of trouble (some times), but his 10 lessons are not enough to make you a successful communicator and authentic, esteemed and relevant blogger - not for your readers, not for the sake of your company and not for yourself!
Robert Scoble starts his 1 - 10 lessons with
1) When you are identifiable in public as part of a company you must be much more careful with using corporate imagery than other people need to be. People get very nervous whenever you talk about competitors or partners in anything but the most glowing terms.
2) Always be sensitive to your boss and what he/she expects to see in public ... , whenever I post I think about how I'll justify my post to my boss, my wife, my readers, the execs, my coworkers. I imagine how that post will look on the front of the New York Times.
for lesson 3 - 10 read them at The Red Couch and keep them in mind. But do deliberate breach this and other rules from time to time. That makes you and your blog much more authentic (and does not always cost you your job)!