We're going to be monkeying with the game server on Sunday evening from about 7pm-10pm MDT. The game will likely be down for at least some of that time and when it's up it may be a little slow.
In accordance with the subscription FAQ, if the game is down for more than an hour or so, all current subscribers will get their subscriptions extended by a full day.
When we're done, the game should run faster when there are a lot of people logged in. That's the plan anyway.