Yammer, the newish microblogging-for-companies service, is in the process of adding a few new features that may separate it from similar services like ididwork (which we talked about here) and Twitter, as well as from conventional email and IMing.
Yammer only allows people with the same corporate email addresses to communicate with each other, which already sets it apart from the others. But it is now adding groups, tags, and threaded comments to its service, which may prove to be the tipping point (ugh, sorry) in its development as a communication device.
I still find wikis such as Basecamp to be more useful overall, but I could see Yammer catching on for folks collaborating within larger businesses.
