Once you pass Steam Greenlight you can setup an Early Access product. But you then need clearance from Steam to publish the page (and product).
We were waiting for the go-ahead from Steam before announcing the launch date and prices. We didn’t want to announce anything not knowing if we would be able to publish the game on the announced date.
Happily, we got the go-ahead from Steam at the end of last week – so expect an announcement on the launch date and price really soon.