Yammer: Coming soon to a corporate domain blacklist near you
That's not to say Yammer's a bad idea. Just a poorly executed one. A better business model would have been to whitelabel a script or produce an appliance that companies could run on their own. Both would sell.
I think it could be interesting to see some sort of quick asynchronous communication tool that was a part of a project management tool like FogBugz or Basecamp but was integrated with your account instead of being standalone.
What does everyone else think?