It launched, but there's a bit of a problem. It seems as though people who pre-ordered the 4-pack aren't able to install it right now.
It looks like Steam changed the name/AppID between the pre-order and the launch version (from Hoard to HOARD, or AppID from 63009 to 63000) so my guess is that Steam doesn't recognize that I own HOARD (63000) because I pre-ordered Hoard (63009).
Though, supposedly, if you install the Demo, you are then able to install and play the full version as well. But it shows up separately in your Library from the pre-ordered edition.