Given the current weight problems with the A380, BA may simply be waiting to see what happens. I have heard that Virgin delayed/downgraded their orders not only because of the LAX problem, but also because of the weight problem. My father, who has been in aviation for 35 years, calls the extra few percent above planned weight as an "absolute catastrophe" for Airbus if not solved properly and on time.
What is wrong with Al vs. Cu wiring, by the way? Not conductive enough?
Additionally, replacing two 747s with one A380 is not really the same for a few reasons (and this is just my inexperienced and relatively uninformed opinion mind you):
1) Frequency issue already brought up here. I cannot wait for the 7E7 to fly long-haul on a small aircraft (maybe) with options to fly several times a day (although maybe not to LHR given the persistant slot problem).
2) Two aircraft gives the airline flexibility in its schedule, able to vary loads by season and days of the week. CPT, for example, will have two daily flights only 6 days/week, and YCR will get extra flights in busy summer months. Imagine, also, if the one BA flight to Hong Kong or JNB is cancelled... what a disaster that will be. With two 747s, there is still the possibility of moving around pax more easily.
3) Some routes are better served by a few smaller aircraft than by one enormous aircraft. Two 747s is still (slightly) greater capacity than one A380, but two A380s might be too much for one route.
4) The sheer size of the A380 may put off some pax. Why do you think we all of this board would kill to have a seat upstairs on a 744? I would only because it is small, private etc. etc. The term "cattle class" will truly have meaning in Y on an A380, and J might merely become an improved version of cattle class.