Some of the comments in here are wonderfully entertaining, both intentionally so and some not so much...
Background: I'm a mechanical engineer (stress analyst) in the aerospace industry (propulsion engines - not GE) with a fair amount of AM experience.
First off, AM for metals in mass production is literally decades away from being mainstream. Never do I think I will live to see the day where anything imaginable is quickly printed in metal, or mail-order CAD file parts are a thing. There's simply a whole lot of labor and post-process steps involved to fully execute a design which are not obvious to the general public. The video above (good job with the details there) does a nice job of outlining some of the steps required for metals, but even then it leaves off a fair bit of detail. Notably, in today's world there is a fair amount of work involved to get a successful build (good print). Usually this requires a bit of experimentation and a non-trivial amount of trial/error. Once you get the process established, you're good to go - but you might spend literally months of time to get there.
Because of the process steps involved, the cost of a product like this (in today's current market) are pretty astronomical. I can confidently say that you are looking at here is a 5-figure price tag PER wheel. Yes, there are steps that could be taken to reduce the costs significantly from this initial prototype, but don't expect a full set of AM wheels to cost any less than 60k (USD) anytime in the next decade.
Creating a self-supporting spoke design would easily reduce some cost.
So would having a machine large enough to print the whole face design, but Arcam doesn't currently make a machine big enough for that (and I don't know who else makes proven/quality EBM machines, if anyone). EOS or Concept Laser makes a few machines which could do it one shot, but then that would be a laser process as opposed to a EB process which would increase the print time (and time=money, of course). HIP'ing is something the industry is on the fence about - it is not always necessary with some alloys but everyone is too afraid to eliminate it just yet.
All that said, knowing what I know I would take a set of these now and drive them on a track without concern. Provided, of course, I could somehow magically afford them.
