Staremo a vedere ....There are currently no plans for a co-op mode. (Hearthstone.de Facebook)
Will new hero portraits be usable in arena?
How does this selection process work? In the settings or when you click 'play ranked'
It'll be a part of the collection manager. - Zeriyah (Source)
Fonte: http://www.hearthpwn.com/news/914-new-m ... earthstone