The problem is the notion that people think that in order for a rumor to be validated, what is being rumored needs to occur. For example, if there are rumors about Boston trying to sign Grant Hill, then some people believe that the only way that rumor is true is if Grant Hill actually comes to Boston. That's just not the way works.
Just like everywhere, you're as good as your sources. Sometimes your sources fail you, sometimes they bring you the good stuff. Like everywhere, some rumors pan out, and some don't.
Celticsblog has had a solid record when reporting rumors... rumors that subsequently have become reported elsewhere with their sources. For the most part, CB takes articles from other places, cites the source, puts a disclaimer with their opinion of the particular rumor, and open up the discussion for "what if" scenarios. So when it comes down to it, for the most part, CB is simply reporting the report of a rumor from someone else. How that suddenly becomes a "CB is making stuff up" situation is beyond me.
I see absolutely nothing wrong with that practice.
Edit: Just noticed that this thread is a couple of months old...