i dont know if any proposal has been official, as of yet. there's been many "close-to's," but i think everything is still in the infant stages.
the most common proposal i've heard is the one you're talking about, four 50 story buildings.
personally, im very against that -- its upsetting to hear.
i loved the towers, not because they were beautiful (no critic or expert said they were beautiful until sept 12th. the traditional comment was that they were "soulless") -- i loved them because they were impressive.
HUGE! and TWO of them!! it was cool just to stand next to them, cuz your neck hurt trying to soak them in -- your eyes could never open wide enough.
personally, i would love to see new towers built, of course in a pair. and id love to see them constucted as the tallest buildings on the planet.
skeptics state that this shouldnt be done any more, as its just "too easy a target." that would make sense if, and only if, at the same time they made that statement, they proposed plans to take down the empire state bulding, the chysler bulding, the sears tower, etc, etc...
until such time, the statement has little meaning to me.
ANYthing is a potential target. you could build four 50 story buldings and have them destroyed in some other fashion -- its impossible to be completely active in a defense.
taller, bigger, stronger, more beautiful, and more safety-conscious designs would empower new york, on every level possible. safety, ego, job creation, unity, etc.
it might take a few years for most to feel confident or comfortable enough to move (back) in, but it will happen (the original towers took 20 years to fill).
the real-estate will eventually be incredibly profitable once more, without question. it just needs people to rely on it now.
(think about how many times san fran has seen an earthquake or field fires? yet its always rebuilt and always in demand. same with japanese ocean front, tsunami-prone property. same with hurracaine-prone vacation spots).
