First off, let me start by saying that this MUST NOT Become any sort of A vs. B post.
and I am just going to point out some facts.
The basic airframe design of the 747, no matter how much you modify it, is 1960s design. Whether this is a good thing or not is subjective, but the basic technology was designed in the 1960s. (likewise, the 737 is basically a 1960s airframe, and the 75 & 76 are essentially 70's technology) - Now I agree that this proves that it is tried and tested. But the Airbus will be designed as a totally new airframe from scratch, allowing radical differences from other, older designs.
Also, (will the 747X be FBW?) the A3XX will be fly-by-wire (obviously) and made of a lot of composite materials. The 747X will have some composites, but not as much as the A3XX, making the A3XX pound for pound lighter.
Both aircraft will have their good points and bad points. I am not getting involved as to which might be better. I am just pointing out some facts.
FLY DELTA JETS
and sail UNITED STATES LINES
N 8 6 3 D A