I've seen this discussed a few times in clan chat, so I thought I'd start a thread about it.
So the new rule is, an opponent can only take 10% of your total loot saved in your clan castle. The rule for regular gold/elixir storage is they can only take 20% of that. Up to 200k.
So think about that for a moment. 200k is 20% of 1 million. So anything in your regular gold/elixir storage above 1 million is basically safe. (Of course this isn't taking in to account penalties and bonuses for varying town halls, but it would be negligible.)
So, theoretically, if you have more than 1 million in both gold/elixir storage, you should move your CC storage over. This is good for two reasons: 1) If you already have 1 million in storage, then they will be able to take 0% of anything you move over. 2) It disperses your loot over 3 or 4 buildings, which makes it harder to acquire.