Reading around on some discussions at other places, my personal feeling on the viability of city to city use is that the biggest obstacles will be noise level and safety concerns having a large rocket fly over/near populated areas.
The video animation showed a very large offshore barge, a whole new class of ASDS beyond what SpaceX is currently using but certainly not an impossible engineering challenge (I do wonder how to handle the rocket exhaust when launching and landing) and it will be several miles offshore. Also, no need to accelerate as rapidly as a vehicle going to orbit. That will help manage the noise levels and mitigate safety concerns. I see the biggest issue for launches being weather related. Rockets have stricter weather parameters than aircraft, though maybe that is just traditional caution and not really necessary.
Of course there are huge engineering issues with routinely taking thousands of people on massive rockets; G-force effects on passengers and cargo, safety and reliability, reusabilty and turnaround times, etc. I suspect they are all solvable.
Some perspective might be helpful. In the 19th century when trains started to go at faster speeds than humans had ever gone before -- meaning faster than a galloping horse -- there was real concern as to whether or not people could survive such speeds. Then automobiles came along and started going faster and faster, and many people were scared of the possible adverse effects. My dad told me about a day in the 1930's when his mother-in-law came home from a drive and talked excitedly about going over 35mph without injury!
I wonder if the number of people who will (sooner rather than later) physically need to travel long distances (global scale, not Hyperloop scale) can justify the huge upfront infrastructure costs. Concorde was totally reusable, too.
Thousands of people fly on trans-oceanic flights
every single day. The demand for long distance air travel is enormous. It will only increase if the flight time is decreased by
over an order of magnitude. Despite the internet and advances in virtual reality, the fact remains that humans like to go places and directly experience other environments and directly interact with other people. That isn't going to change any time soon.
The Concorde plane could only seat about 100 people, used enormous amounts of fuel and reduced flight times across the Atlantic by about 60%, but ticket costs were stratospheric (as were aircraft costs). It never made economic sense. The market was too small. Also, the plane was cramped and incredibly noisy. Since the Concorde ceased operating there has not been a viable economic case for a new SST. Though some silly ideas have been proposed, like this 12 passenger "business class" SST
Airbus reveals the ‘Son of Concorde’ will fly in 2021 at speeds of over 1,200mph | Daily Mail Online
I also noticed Elon was more flustered than normal.
I noticed immediately that he seemed different than during previous public presentations. I think it was a very emotional day for him: 9 years to the day since the first successfull F1 launch and SpaceX is at the point of starting construction on the spaceship design that will take humans to Mars. He was presenting the plan to the world, a plan that he truly believes is achievable in the next decade (even if the 2022 launch target for the first cargo missions to Mars is "aspirational"). I think he was overtaken by the immensity of the moment. Yes, a year ago he presented his Mars mission plan in public for the first time, but at that time he did not know how SpaceX could fund it. Now he believes at least the initial phase of the Mars mission can be funded just with SpaceX revenues, and it is starting to become very real to him.
