It's limitless on how we get out of beta 3 .. but we still have beta 3
I feel like Beta 3 has infinite playability, the gameplay feels pretty much perfect at this point. As for content, I feel like there's more than enough to satisfy, with allmost all the guns and gamemodes being included, as several excellent-looking community maps coming soon (like Major's Dam) to add to the already awesome release.
I think we, the fans, could go quite a while while waiting for beta 4.