Winglets
With regards to the winglets on 744s, as I understand there is a company which offers blended winglet replacements for this aircraft. It provides some economic benefits from the "factory fitted" ones.
Whilst a little iffy in his address, 747FOCAL does have a point regarding upper deck evac of an A380, so people may well baulk at such a "ride." However, I am confident that this is an issue Airbus will have addressed.