I think that there are three main areas that could use some serious turtle-love:
1. Clans. The whole CC clan experience is growing exponentially, and yet we still lack some really basic necessities, like game creation and labelling privileges for clan leaders (or at the very least, for jp and marval, special dispensations aside), to say nothing of the whole OTIS thing. But a few small changes would make clan challenges and leagues ever so much easier to run.
2. Site mechanics. Really, the freestyle loophole has to go, and should have been fixed long ago. This won't be the first time that a deep flaw in freestyle has had to be fixed. And as long as there are identifiable flaws/loopholes in freestyle, it will continue to be a stigmatized game setting.
3. Gameplay. It's been ages since CC had a new gameplay feature, and while random maps are all well and good, they remain something of a novelty. Infected neutrals also sound cool, but again they seem like more of a novelty than anything approaching a killer app. However, team 1v1 games would, IMHO, give the site a major shot in the arm. I recall the heady days when 1v1 games were first introduced, and game creation took off like an ICBM. While team 1v1s may not be quite as popular, they would certainly fill a huge niche and would become very popular.
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