I'm quite impressed at how well the A380 fared from all the damage; the spar damage would have resulted in a lost wing in aircraft of not too many years ago (including many still flying!). That is the positive aspect -- the engineering has successfully created redundancy in critical systems such as the structural support of the wing. The negative aspect is that systems which were thought to be sufficiently redundant and never a single point of failure, such as the dual wiring routes to the engine controllers, were destroyed by a single event (2 separate pieces of shrapnel from the engine). Also some of the software behaviour was not optimal (though presumably as intended, just not as expected by the pilots).
It looks like RR is replacing 40 engines (with a value of over $10 billion), while there are likely to be software changes from Airbus at a minimum ... though the worst case could be loss of certification due to losing engine control from a single failure. The inability to pump fuel between tanks is maybe the most serious failure -- that could have crashed the plane particularly in alternate law mode which was activated by the initial failure (something that the pilots never expected).