That is actually planned. We already support it for Google Contacts, but we also plan to support generic CardDAV/CalDAV “client-mode” in the future.
27 votesSeth commented
This would be very helpful. I much prefer vCard but run into problems importing vCards that stuff multiple entries into a single vCard file, and just the general lack of application support for vCard. Offering a .CSV import onramp for Fruux would greatly ease end user pain.