There's bigger forums than this on the internet so I'm sure it will manage just fine. The more users we get the more they'll likely make in advertising so it shouldn't be a problem.
Ah, I didn't factor in more users = more money due advertisement, it should be a direct correlation so overtime let's hope enough money keeps being generated by these forum ads. My Adblock Edge isn't blocking these advertisements so they must do it in a really clever way or something.