I don't even play Minecraft but the news that Mojang are making the Java edition source open for modders with zero obfuscation is super cool.
@gsuberland has been the logical thing to do for some time. Minecraft as a product has been a sign on, account management and anti-abuse service in value terms not a game for some time. If anything they should be helping people integrate Minecraft logins as a single sign on service for other things :-)