Panda-K-Bear, I'll disagree with you on your point that the 747 Advanced is a paper airplane. This airplane is different from the earlier 747X, 747-500/600 proposals, because the economics of the Advanced are different from these earlier airplanes.
In the current environment, operating economics (and to a slightly less extent operating flexibility) drive airplane sales more and more compared to purchases made in the past. For the 747 Advanced to work, it has to have excellent operating costs. It already has (on paper) very good operational flexibility (available airports, freight capacity, etc), but its seat mile cost flexibility (good seat mile costs in a variety of circumstances and routes) have to be among the best available, something the current 744 does not have.
I know that much of the design criteria for the 747 Advanced is geared toward these goals, and I personally think that Boeing may well launch the airplane if they can get these numbers right.
What concerns me the most about the A380, is its operating economics, where weight is THE issue effecting its operating costs.