I know that many in the Celtics organization read it daily. Though I've heard that Danny dosn't - and perhaps that's for the best too. 
wow...that kinda gives me a new perspective on this blog and what goes on here. TP for you Jeff, for all your work! (though a tp is hardly proper recompense)
I would expect that some read it since many are involved with the Celtics because they are fans. Like other fans, they mike exposure.
I'm sure there are many different opinions within the organization or many issues. While Atlanta was the most public disagreement among owners we have seen in recent times, I'm sure many teams with multiple involved owners have disagreements, but defer to their President or GM. I could see them enjoying reading discussions.
There are also many people who read Celticsblog for the links and who do not bother with the forums. Like all forums, for every Roy Hobbs cap clarification post or cordobes Euro-player evaluation, we also have a ton of sign Toine and Doc is a fool to not give POB minutes.