> I wonder what kind of future this spells for quantum computing - will it continue to spread or will it be limited/stunted by being controlled by only the few?
I feel like this is a step in the right direction, though. Right now using quantum computers is totally outside of the realm of possibility for the vast majority of people - they're simply too expensive in materials cost, expertise to create, conditions for operation, etc. etc. etc. - without services like this one. The only chance an "everyday" person has to try out a quantum computer is to rent time on someone's else's.
I don't think at a similar point in the life of classical computers we had options like this that were readily available - you could rent time on the computers, but I can't imagine that getting access to them was as easy as it will be today with the internet being a thing and service providers offering high granularity on billing.
My understanding (and I'm not even remotely an expert, so I could be totally off base here!) is that it's an open question on whether or not quantum computing will ever even be doable in environments where classical computing works - it might not be within the realm of what physics allows for it ever to be possible to have a quantum computer powered smartphone.
I hope access is ubiquitous someday for people, but in general I feel like this is a good step while that's not practical.
what would an everyday person do on a qc?
The everyday person will use QC like they "use" machine learning today: from a very high level abstract viewpoint, where services they consume have a little bit of intelligence that makes interacting with them more efficient.
It seems like neural networks should map to it well. Once the degree of connectivity and the number of qubits approaches the millions, there's no way any normal software solver is going to be able to keep up with it.