It won't be 0.4
That's a major update.
Survival was a major update. As was crafting. Furnaces aren't a major update.
It will be a bug fix/block add version.
It's updated at least once every 4-5 weeks. So expect an update within the next two weeks. Should be out before June.
But that doesn't mean it will. Remember, it has to be verified before submission. That takes a while. Check back every day. It is updated overnight EST. (midnight in the US, in other words)