KE's first A380 route is supposed to be ICN-LAX. If I were to guess on the 748, I'd imagine they'll go to longer routes currently flying 744s, like ICN-ORD.

Interestingly, the ICN-ORD route used to be 744s during peak times and 772s the rest of the year, but has been 744s year-round lately, so maybe that route might be a candidate for A380s down the road.