I did not mind at all posting in other people's blogs. My only hesitation is I am a terrible speller, so it makes me hesitant to write too much. I don't think it is any different than sharing with a teammate. It actually could be better because if someone else can learn from something that worked in my class, they wouldn't have to talk with me directly to try the same experience in their own classroom. It could really shorten the learning curve for new teachers - learning from more experienced teachers blogs.
Here's a site I plan to investigate further.