I Came across this very simple video that outlines the difference between microblogging and email. This can either be looked at as an internal process for only your company with a platform such as SocialText Microblogging. It can also be looked at as an external process for your company with Twitter. 
Either way, your company employees can have the ability to have open discussions with others to see and respond to rather than having ALL conversations in a closed environment such as email. While there are times for use of email in a closed environment, much collaboration and discussion can be held with multiple individuals over an open microblogging system.
