Much as linking/importing email to Agenda is a valuable tool, I know that linking contacts from the Contacts app would be extremely useful. I’m sure many others have people/organizations that they are making notes where they are related to a specific person, group of people, and or orgainzations.
At this time, I can drop a vCard into Agenda. That is okay, but the behavior is not. If I drop a vCard into Agenda, the behavior I expect when I click on that attachment is either opening the contact card in the Contacts app, or showing me the contents of the Contacts card. What I don’t expect is for it to attempt to import the card back into Contacts.