How can I play Blu Ray discs with my MacBook?
VLC 2 on Mac has experiment support for BD playback. That should work with an external drive of your choice. If you don't need a native player, you can always run a VM and have your pick of Linux or Windows Blu Ray player software. 

Vlc can't play decoded commercial Blu-ray discs as I know. But Macgo have got the BDA license already and can decrypt Blu-ray codes legally.