I'm always slightly wary of whistle-blowers, they usually have a grudge of some kind, and this man seems to be no exception. However.... Boeing will have to demonstrate that the aircraft is at least as safe as a conventional aluminium one in a crash, and that isn't easy. I'm sure the FAA will keep this scare story firmly in mind when they evaluate the data.
I'm fairly philosophical when it comes to this kind of thing - I have to fly quite a lot to earn my living, so there's not much point in dwelling on the dangers. Flying is the safest form of travel by far, and if I'm not involved in a crash I'm unlikely to have to worry about whether the carbon construction will 'shock' me.
See you on the Dreamliner.