Video and Guide found here
http://www.wowcataclysm-wiki.com/dungeons/bastion-of-twilight/halfus-wyrmbreakerFor the updated boss mechanics ( the video has now been updated)
Looks like a fun boss =] the video is not a kill but it explains the jist of the fights and shows most the boss itself until they enraged hehe.
Just remember you can release the other dragon during enrage to reduce dmg the boss does.
So Have a look!
Boss mechanics may change.
Will Update.
