Basically Buestreak is like Instant Messenger for your project team, Bluestreak allows you to create work groups based on your your team members for each project.
Bluestreak is a Cloud based application that you can access from the web as well as your desktop.
Bluestreak has been around for ages!!! But since we've started using it in collaboration with Revit Server it's really come into it's own now. It's a lot faster communicating with team members letting them know if you need a sync or a workset. Bluestreak automatically informs you when team members have saved to the project which can be handy when to sync from central. You can connect different Revit files to different groups so that if you switch projects only those that need to see the Save to Central info get it. So your not spaming everyone.
I also found out that Bluestreak is also a Transformer who had to change his name to Silverstreak in 2003 for Trademark reasons... I wonder if it was Autodesk??