Axel suggests that Mozilla Weave should sync Infocards.
The Weave graphic that Axel adds Infocards to makes reference to 'friends & family' - implying some social aspect to Weave.
Hopefully that doesn't mean using Weave to share site credentials with your social network. Social sharing needs to be more granular than the 'all or nothing' that impersonation enables.
I've yet to hear the Infocards social story. One thing for sure, I do not want to be tracking & managing cards given to me by my friends & family - each card reflecting some set of 'sharing rights' assigned me by the owner. That way leads to madness.