The outer engines on the 380 are a problem for FB
ingestion. Brisbane airport will need to spend quite a lot of money to eliminate FB
ingestion problems for the 380. Sydney can take the 380 but sydney airport has no significant future development potential because of lack of space. Where are Qantas going to service there 380's. ( My bet is some arrangement with SIA) Qantas is in the process of moving their heavy jet maintenance to Brisbane. so should Qantas be paying for the upgrade to accommodate the 380? Although the total weight per tyre is on a par with the 773ER the overall weight of the 380 is higher, so in some cases culverts, bridges, etc may need strenthening.
It is often said that airports around the world had to adapt to the 747, but i don't think the situation is analagous. The 747 was a quantum leap over the 707, but the 380 is a modest increase over the 747, in terms of capacity.
I think the real show stopper with the 380 could be noise. Not engine noise, but airframe noise. If it doesn't meet future standards, it will be fun to watch the European Govts twist and turn to find ways to let it in!