So apparently now that Minecraft is fully released this is the new Mojang release "Cobalt":

http://playcobalt.com/

Cheaper purchase for the alpha just like Minecraft.

Alpha

Pre-ordering costs 9.95€
Local multiplayer
Introducing the singleplayer/co-op main campaign
Introducing the level editor
Windows only

Beta

Pre-ordering costs 14.95€
Fully functional level editor
Continued work on singleplayer/co-op main campaign
Introducing in-game level sharing
Introducing more editors
Windows, Mac OS X and Linux

Gold

Buying costs 19.95€
All editors fully functional
In-game level sharing
Completed main campaign
Local multiplayer

No online multiplayer ever....and i personally think the game looks like shit. Also lol no apple in the alpha. Client is about 148mb so it may be larger than Minecraft.