It is something on Kovid's long-term TODO list.
Someday, calibre-server will have full read/write capabilities and be able to run the complete GUI with access to all metadata and book management, plugins, etc. -- the works. Or so I gather.
That would allow remote management via a server/client model, and open the door to multi-user mode.
Also planned is a cloud version of ebook-viewer, which will apparently support a bunch more features.
As you can imagine, this will be a major undertaking. There is no ETA.
But yes, the need has been noted.
