A recent Blizzard Entertainment forum thread listing the Hearthstone closed beta known issues reveals Blizzard is currently working on Macbook Pro Retina display support. The iPad Retina display might be a candidate as well considering Blizzard plans to launch Hearthstone for iPad in 2014.
via N4G: pc news feed http://n4g.com/news/1369557/hearthstone-support-for-macbook-pro-retina-display
via N4G: pc news feed http://n4g.com/news/1369557/hearthstone-support-for-macbook-pro-retina-display