This might be useful if we ever build very slow, small and cheap interstellar colonization ships. Basically, I'm picturing something like a seed from which an entire civilization could hatch. In practice, it would be a tiny fabrication plant, plus lots of data. Once it arrives, the thing would use material from an asteroid or a comet to build larger and more specialized 3D printers, which would turn asteroids into a habitable space station, bioreplicators, etc. The bioreplicators would produce living germ cells from DNA data, artificial wombs would gestate them, and very fancy AI would parent the kids that come out. It's fun to think about how tiny the initial payload could be so that it's still big enough to eventually get the job done. Probably, the best way to do it would be to start with a single crude and tiny 3D printer, which is able to make a larger, better 3D printer, and so on.
Obviously, a big proportion of the mass of this thing would be the storage medium that carries all the data, because you won't just need software, videos, libraries, etc. You'll also need genetic info for an adequately diverse population of humans, plus an adequately diverse population of all the other living things those humans will need and want to have around, like gut bacteria, broccoli, earthworms, butterflies, kitties, etc. That's a lot of data, so you obviously want a robust and low-mass storage medium for it. The trip might take thousands of years, and space can be nasty. But if this DNA-in-glass medium can reliably last millions of years - more at 3 degrees K, I presume - maybe it would do the job. It would be really cool if it turned out to be possible to reconstitute our civilization in another solar system from a seed no larger than a trashcan. I don't see any reason to think it's impossible to go even smaller, maybe to the size of a beer can. The smaller it is, the easier it is to accelerate and decelerate. If it rides a laser beam on the way out, and decelerates with solar sail (like a parachute), it might be practical to make thousands of these rather cheaply. Any seeds that germinate could then make thousands more. (I think Freeman Dyson once discussed an idea like this.)