Here's one thing we can do in addition to clamoring for a season 3: show Cartoon Network that we would love to see a 6 episode mini-series set within the season 2 timeline.
It would bring the episode order for season 2 up to 26 episodes, so that the spread of episodes between both seasons is even and so that the Team members added after season 1 could be more fleshed out. Season 1 covered 6 months of the year with 4 months getting 4 episodes each, and 2 months getting 5 episodes each. The mini-series could take the form of an episode set at the end of January, one set in early February, one in early March, one in late April, one in May and one in June.
It would be better than nothing, and is a more achievable goal than a 26 episode third season (I have a hard time buying into the possibility of a 13 or 20 episode third season, as you don't usually hear of these sort of shows ending on strange episode numbers like 59 or 66). A 6 episode order wouldn't require the production team to reunite for too long and wouldn't incur too much in the way of costs compared to a 13+ episode order. Who wouldn't be pleased to see the show at least get to 52 episodes?
If we show enough support and a sustained interest in the show over a prolonged period of time, we can hopefully accomplish this. Please spread the word about this and mention it to Cartoon Network in your e-mails and letters, because we stand a better chance of making this happen.