I hate to resurrect an old thread, though it's still on the front page here in the World section, but I have some insight into this specific topic based on my experience in another game with a smaller player-base and it may keep some of the newer players around.
I was an avid VTOL pilot in MechAssault 2: Lone Wolf. In the multiplayer Conquest mode, the Inner Sphere factions were each given a set of planets at the start, and factions fought for control of further systems via CTF/deathmatch (each system had a gametype specifically chosen for it). Five factions existed, and the player-base, though small, seemed quite stable and actually increased slightly after the initial mass exodus from the game. The release of the Xbox 360 doomed the multiplayer aspect of the game almost entirely, but I wouldn't worry about that scenario for GoIO. Lots of PC exposure seems to really be effectively getting the word out to players, and as soon as the influx of trolls and miscreants die down, I think we'll enjoy a stable community that increases gradually.