Hey all--I heard back from the Massdrop guys again today. Right now, it's looking like the Ergodox buy will be ready to go in January, and will probably run for about a month.
Also, because 3D printing doesn't scale well Massdrop will be offering only litster-style cases, although they will offer it with and without the wrist rest. Those that have their hearts set on the dox-style case can go PCB-only for the buy and order one up on their own since the total cost to the buyer would be the same either way.
Finally, I brought the criticism to them concerning their registration wall, and while they sympathized (after all, it's something people don't like), they need to keep it in place to continue doing business with their suppliers, who from what I can tell essentially demand it. However, since there's no brand to keep happy with Ergodox, they've offered to try to make the Ergodox buy public and freely browsable, as a gesture of goodwill.
Hopefully this type of public implementation could be extended to other group buys in the future, for products that aren't simple retail goods (e.g. caps)? Those are my thoughts though, not their suggestion.