An educated guess, looking at how long it took for a patch that pretty much changed the game entirely, then a patch that brought us a new boss fight on only one world. I speculate that the future world or the game finally being fully released, will occur by July 17, 2014.
God I hope I am wrong, I wonder how many people downloaded this and how many still play it at least once a week. --- DOOD!!! ~Prinnies