This has proven to be quite a decent thread here and after one of my classes today, I thought I would chime in again...
One of my professors is a 20 year veteran controller at Miami center and was telling me they are routinely routing all flights from Central and South America going to ORD over the Bahamas and are pulling 20 miles in trail that far out as requested by ZJX. ZTL is being requested by the center to their north and so on... The NextGen ATC will primarily help the centers flow traffic in a more direct route, and thus creating more congestion at the airports. There is absolutely nothing we can do about wake turbulence and the separation involved with it. If we were to reduce minimums, we would be compromising safety. Eventually in time, airports may have a way to create a windshear machine to break up the vorticies, but there would be a whole new safety aspect involved with this... Nothing we have technologically at this point is even remotely feasible to reduce congestion.
I understand the runway layout at ORD is a nightmare but proper staffing and utilization of current infrastructure would allow a great deal more LAHSO operations and help flow run better, but if they get the shaft from ZAU and ZID, who are only running more traffic, more efficiently, the situation will go from siht to "oh F"...
As for LAX, I really hate to be the one to say this but with having a few contacts there, I would like to try to shed a little light. I will be very politically incorrect and say a great deal of the problems with runway incursions, and other issues at LAX is the extreme influx of foreign pilots. You will see the same thing at MIA, only MIA is mostly dealing with latin carriers whereas LAX is dealing with carriers who routinely forget that English is the official language of aviation (they mostly say the Asians are the worst with this).
No matter what happens, technology will evolve and so will people but with the current lack of staffing and support, there is only so much we can do with what we are given and until staffing and support are improved, no technology will make anything better...
My$.02