Version 1.6.8, a stable release, is now ready for download in the account manager.
If the waves of drifters annoy you, get this update, otherwise it's not required 
Game updates
- Tweak: Reduced drifter spawn chance by a factor of 10
- Fixed: Game crashing when trying to connect to a multiplayer server more than once
- Fixed: .clients commands not listing players out of range
- Fixed: Might fix crash reporter not launching on windows and mac
- Fixed: A number of small memory leaks when exiting a game world, spamming the log files
API Updates
- Tweak: Documented the ItemStack Constructors and Properties
- Tweak: player.WorldData.PlayerName now always available, even if the player entity is not loaded
- Fixed: player.Entity not null when the player entity despawned