I'm thinking around 2K, dropping rapidly due to swimming bears, but then gradually increasing with updates. but this is a pretty wild guess.
I'm sure once the server starts, if we get people who make youtube videos and stuff picking it up and playing with it, that could draw in a lot more people, but its hard to draw in new people with limited information about the game.
(If the world is 5SGx5SG, we each get around 31 minimaps, or ~1 (and a bit) localmaps, with that population.)