I think it'll still be a virtual machine? It'll just mean that there could be an ARM native virtual machine rather than one emulating x86.
(Yep you need ARM Docker images when running on ARM of course)
I guess to some extent that might be generally useful, what with things like AWS's Graviton ARM processors, but I expect it'll take a while.
[1]Especially now that public docker hub is ip rate limited to uselessness.