Very good, but it's not transparent, and so can't be used in glazing application the way aerogel could (I'm think thin double glazing, no more than 12-13mm / 1/2in thick), although maybe as a window frame...

Could we at least not use "strong" and "stiff" interchangaably? This is supposed to be about engineering.

All very impressive, but it is difficult to see a practical application without major developments in the production process. Whilst it might be possible to manufacture prototype components using this process, unless they can be turned out at mass production volumes, what value any test results from the components in developmental use.
I suppose the exception would be space vehicle components, which can hardly be said to be mass produced, anyway.
Over and above those considerations, I suppose the major concern would be its performance under overload condtions. I expect that they would produce a sudden catastrophic collapse, which is not the best outcome most of the time. Though how you make it malleable in order to increase its resilience is an area requiring further work, I suspect.
Materials such as this will have come of age when they can be used for making the reciprocating components of an ICE and perhaps even the cylinder block. I suspect that crash worthiness requirements would preclude their being used for vehicle body shells and suchlike. Though this is not too negative a point because there might come a time when vehicles could be so lightweight that one could not go out for a drive in wind conditions above six on the beaufort scale and crosswind parking would form an essential part of the driving test. As for fording a river, forget it if the water comes above the hubcaps.

I think this was announced a couple weeks ago. That or someone with micro latices using a very similar fabrication method was announced.
This is awesome work. Once the speed of manufacture increases this could replace structural components that are currently very heavy solids at the moment. I remember seeing a graphic from one of their competitors showing that using micro latticed steel a 1 ton 1 inch thick steel plate could be replaced by a micro-lattice that weighed a pound or less. Imagine a tractor trailer that only weighed 2 tons rather than the current 15.5+ tons.
The speed of manufacture is the current limiting factor, but there are groups working toward solving that issue. This document (http://www.researchgate.net/publication/51808274_Ultralight_metallic_microlattices/file/9c96052505d79b0797.pdf) is from a team developing a scalable process they think could generate several cubic meters of the material per hour.

I'm still waiting to see the killer applications using AeroGel for something.
AeroGel has been around for a long time, but it is still little better than a novelty.

Imagine this competing with carbon fiber and Al car bodies. The pressure to lower manufacturing costs would give us inexpensive, ultralight cars. Next, we need computer generated & air tunnel tested aerodynamic design like the Aptera. Suddenly BEVs will have 4-500 mile range. All that's left is to come up a quick charge (under 10 minutes) and bye-bye ICE.

The implications are spectacular! A brick of this stuff, wrapped up in an airtight membrane, "containing" vacuum, could be the basic building block for incredible airships!!
Remember; Vacuum is lighter that Hydrogen or Helium!
Even floating cities, like the one in "Star Wars, The Empire Strikes Back", should be feasible.
The only drawback is the huge amount of "Cavorite" needed.
...for now...

As a filmmaker, this is exciting. Among many other uses, if this could be mass-produced it would make great combination soundproofing/structural walls for sound stages. If the cost was reasonable, the walls could be much thinner than what is currently used in sound stages, reducing costs and real estate requirements. If the cost is low enough, it could also be used to make the walls of sets light enough that a single person could set them up and break them down.

Mass produce, awesome, many uses for.

@Alfred Max Hofbauer
Disturbingly you might be correct. The problem with this has always been strength under compression. The back of this envelope I have in front of me suggests that this material is strong enough to support such a structure. Or at least within an order of magnitude of strong enough.
If it can be increased in strength one hundred fold as the article suggests then it might compete with Helium for lift per unit volume.
Not sure it would ever be economical compared with just plain ol Hydrogen though...