If you are looking for a true standard module solution you might want to look at using the forums module.

You could have a different "Forum" for each of your projects, you could grant only the project members access to the forum if desired.  You could configure it so all users could post and reply. 

You would just need to set an internal rule that only ___ Items should be created as a new thread if you want to limit the content or force a structure....

Blogs belong to a specific userid and it is possible to use a setting on the display module to limit the display to a particular users blog.  We do this on many of our project pages (e.g. http://www.dotnetnuke.com/tabid/820/Default.aspx) where you'll notice the blog entries for the Project Leads.  This is limited however, as the other blog features (like the archive, etc) still consolidate info.  But it is a pretty easy way to give a more "announcement" type feel to particular area and may be of help.

You can also be looking for some updates to the Blog module soon... more on that later *grin*.

Scott Willhite, Co-Founder DNN