Sunfish - whats wrong with Engineers talking about structual failure? I am one. I happen to be a Pilot too.
Airliners are not designed to 4g, the usual limits are what has been stated above.
The fact is that the 150% is an aim and the wing failed that aim. Certification requirements are there for many reasons - and this wing didn't make it. As I said above though, it could be a simple fix, or indeed something much more serious. We are not saying the A380 wings will fail in light turbulence, or even in a TS. What we are saying is that the aircraft hasn't met the requirements - the reason for this is unclear and so the ramifications of that are unknown. Could it be that the aircraft will fail in a TS one day after 20 years of service, or could it be that the failure is easily fixable and nothing to worry about? For your info, severe turbulence can be encountered without warning, in clear air and have a very sudden onset - its not just about TS.
Superpilut - your analogy is a bit too simplistic. Structural Engineering is a bit more complicated than answering a few questions on a piece of paper. It depends why you failed the test. A good examiner will write an exam that tests all your areas of knowledge - if got your 74% by demonstrating good knowledge of all but one of your subject areas, you may only be re-tested on the one you failed. Do you see the difference?
Daily Mail readers - well you just can't explain to them, that's half the problem!