Going over the planes that have been changed for the purposes of Urban Planescape, I noticed a possible omission:
Have the elemental planes been changed at all by the shift to modern times?
Thanks
Luc "I doubt it, but it's worth asking anyway" French
Makes you wonder what cities in the Inner Planes are like, huh?
Well, we had the Elemental Express prior to moving to Planewalker.
Basically, it was a train set on infinitely long pillars(except for on Earth) that ran the circumference of Water, Air, Fire and Earth.
Electricity is probably more popular name then lightning but other then that, the innerplanar "nature" would probably stay the same 
Fire has solid ground too; you wouldn't need the infinitely tall pillar there, either.
I don't think the Elemental planes were changed - fire, water, earth, and air haven't really changed - but there might be a new type of demiplanes similar to quasi and para that are made of various substances.
Perhaps the Pseudoplane of Cyberspace has a portal to the Quasielemental Plane of Lightning as the Internet and data is made up of a bunch of electrical pulses.
The general idea, when we've discussed this in the past, is that no, the inner planes haven't changed. The inner planes are substance. They are the building blocks of the multiverse. Societies in them can modernise, but the planes themselves shouldn't.
We update the outer planes because they are forged by belief - the populace of the planes becoming modern will influence the form of the outer planes.
Pants of the North!