Seriously, please don't just post on twitter and rely on people finding it. Most people only found out about that twitter post regarding the maintenance from other players here. When you make an announcement, it should be replicated on all available mediums, but more importantly, it should be on your forums under "announcements" because that's where a lot of people are looking and is the standard for games.

Also, keeping conversations going with the community while you have the game down would do wonders in assuring players that they're not being ignored. I also hope you're looking at promoting people here who have been helpful so far to Moderator status (no, i don't want to be one, just want that to be clear). Mods would help you manage the community as well.

Good luck and more power to your Engineers and Community Managers.