As a note, though - I'd definitely like to be able to select which profiles sync, and to which machines. I think they should sync by default (especially once domain/regex matching is implemented, that list will be a nightmare to maintain manually), I would also like to have a "Work" profile that doesn't leave my work-machine, while still syncing most of my general-browsing profiles to my work-machine.
No ideas on how to make it a smooth UX, but expressing the full matrix would be ideal — there are definitely use-cases both where 1. "I'd like this profile on all my machines, with <this exception>"; as well as 2. "I'd like this machine to not have most of my profiles, with <this exception>."
