Early, but reasonably brisk, Alpha. The aim is to ferret out most of the basic of basic potential issues and headaches...then pour in content to them...then introduce additional overarching ones like Magic, and repeat that cycle on into the sun. Essentially, avoiding the ADOM mess whereby things got so far gone on so many fronts and technical cruft that Biskup can't intuitively DO anything compared to the likes of this. The whole Java 7/8 thing will also probably be a factor.
So yeah, much is still in flux, but people are having some fun with it aside from trying to hurry up and break everything they can so that it can be fixed and not impeded the goodies to come.
I hope he gets enough donations to get that new machine he's hankering for to speed things up even moreso, so say nothing of any potential stability woes...