Carbon fork - possible crack.

the carbon fork leg should not catastrophically fail, carbon will go soft/bendy; as mrveg says the stress crack is where the drop out is bonded into the fork leg...it may be possible to repair this, worth asking around, maybe try Argos cycles in Bristol http://www.argoscycles.com/

A fork going all softy and bendy while you are braking for a downhill corner. Sounds delightful. Or perhaps whilst changing direction on a busy roundabout.
Whatever it won't be pretty or pleasant.
It might be repairable, but for the price of a new one it isn't worth it.