There are very specific applications and implementations that make sense on Google's smartwatch platform. Minecraft isn't one of them. Even so, the first batch of Android Wear devices have at least as much processing power and memory as some of the older or cheaper smartphones, so it was only a matter of time before someone tried something like this. That someone is YouTube user and Galaxy Gear owner Corbin Davenport.
Corbin says that he didn't do anything special to get Minecraft: Pocket Edition running on his Gear Live, just manually installed it (I'm assuming he used the standard ADB commands).