An enormous effort, but 1/2 a kilometer of tube with all the apparatus to lower the air resistance is a long ways off from hundreds of kilometers if not thousands of kilometers.
How are the teams dealing with land expropriation, thermal expansion, service & sealing, not to mention ingress & egress during regular runs, and emergence evacuation to name a few issues.
The biggest factor is of course travel cost per kilometer and ROI, they must know this at this point. Almost anything's possible with enough cash and unless they can prove to make money in their lifetime then investment will stop.

Nothing really new here MagLev has been around for decades, Now the Cargo aspect may just be a winner Think of that package in the same day.

To the other commentors, I encourage you to read the Alpha document. Concerns like "thermal expansion, service & sealing, not to mention ingress & egress during regular runs, and emergence evacuation " are all covered, as is ROI and how the Hyperloop significantly differs from Maglev designs.
And it's not super hard to read.
Just look up "hyperloop alpha"

travel cost per kilometer..... Thats been my question from day one, how can they move enough people to pay for this thing? .. There are already above ground maglevs in service that can move 200 plus at a time at speeds up to 400km/H .. but the build cost is higher then traditional high speed rail, the Hyberloop would be even more expensive up front, not to mention the higher cost in use, due to the added complexity of the vacuum tube .. I would to get my hands on the perspective they are handing out to investors.

Heavier than air machines will never fly. And passengers in a horseless carriage will suffocate at more than 20mph.

Elon Musk's ventures all suffer from scalability issues. Hyperloop one is no exception. It's cool to put together 1/4 mile of tube and a whole bunch of technology, but scaling that up to hundreds of miles is a nightmare.

It would be best if Elon Musk and Shervin Pishevar left the vacuum tunnels and soon developed multiple magnetic tracks for individual and collective suspended capsules, without motor or batteries, powered by solar energy, wind or hydrogen. In doing so, they would probably be inaugurating today the future of world transportation, a preview that would resemble and truly honor the genius of Nikola Tesla.

Maybe this could evolve into a vacuum tube satellite launcher.

Makes me think of Solar Impulse : It worked pretty well if you estimate that a round the world in sevetal months is wooaw.... And what next ?

Well, 192 is an advance from the last test. I wonder if it might be better to make these wind tunnels and blow 'em down the line.