What should I do to secure my bitcoins?

First of all, remove all bitcoins possible from banks/exchanges/"hosted wallets". If you can't export your private keys, then you don't actually control the bitcoins. This is a good idea in general, but it's especially important in case of splits. If you're using a Bitcoin bank, then you will have no control over what happens to your coins. Quite possibly, the bank will end up stealing/losing one of the currencies that you should have access to, either through greed/malice or technical incompetence, and the currency they throw away might well be the only one that ends up having any long-term value.