How useful is that, really, considering you couldn't possibly use a Yubikey to configure disk encryption? Unless you actually put the unlock key on the Yubikey somehow (I've never heard of someone attempting or succeeding at that), anyone with physical access - which is what this is intended to protect against - could still wreak all kinds of havoc with disk access.
It's certainly easier and may even be safer (in the case of a malfunction, which has happened on OSX) to just use a longer password.
It's certainly easier and may even be safer (in the case of a malfunction, which has happened on OSX) to just use a longer password.