Video broadcasting application for OS X
Would UStream be what you are looking for?  

Ustream is a free service (with a paid upgrade) for streaming from any platform to any platform. Users can view the video stream online or via a native app (iOS and Android). I highly recommend Ustream, as it works great and (best of all) is free. You can broadcast from the web interface:


Or from Ustream Producer (free), which is a native app that runs on both OS X and Windows:



Ustream Producer has many features including:


Screencasting
Single camera broadcasting
Save broadcast to watch later
Importing movies, stills and music


There are two paid upgrades for Ustream Producer, Ustream Producer Pro ($199), or Ustream Producer Studio ($549).

Ustream Producer Pro includes all the features of the free Ustream Producer, but also adds:


HD broadcasting
Multiple camera angles
HDV camera support
Titles, Layers, and Picture-in-pictures


Ustream Producer Studio adds:


Chroma Keying (green or blue screen support)
Audio Sync Delay
IP camera support


I highly recommend Ustream, as we use it for church and it works great!