For blogging - and many other purposes - we'd like to make it easy to add links to Tweet, like on Facebook, Google+, email, etc. the card you're looking at. (And the site as a whole.)
This will be a module, perhaps with something like *share+*right+*structure such that +*share will shows the sharing interface to share the card it's plussed to. We'll also want a way to share the base URL of the site, maybe that just goes in *share.
We will select one of the many existing multi-share services so that we don't have to code the whole thing ourselves.
emergingleaderlabs.org has done it by hand
The APIs for the social media services will likely be either JSON or XML, and we should develop a more general set of features to format Cards as JSON/XML. I good :core layout in each data format can be adapted through automated processing to the specifics for a particular API. XML with XSLT translation would be sufficient. For XML browser rendering, the XSLT is really the "style sheet" and will use same/similar web api features. I don't know the similar tools for JSON, but I doubt we have to re-create this from scratch.
When I was first playing with XML rendering, I was thinking that we might have an additional setting similar to Default Layout, but for XML (and similar for JSON). Ethan probably has some better ideas by this point.
You probably will need a setting per API. *twitter_post, *fb_post, etc., otherwise we can't give all options for each card. We do probably need it to be a setting so it can vary on patterns, so it will push on Ethan's desire not to add to many codenames/settings. I think we just need some rules/patterns about when we can/should add these items to the official set and how pack developers can reserve them.
I don't get what those settings would do, but look at what emergingleaderlabs.org did. This is a simple thing to do reasonably well with a plugin. Would want justification for all the added complexity.
Gerry, are you imagining us coding something like this ourselves? Ethan mentioned somewhere that for starters at least he'd like us to just pick one of the existing share-with-many-social-media-services things and just use that. E.g. emergingleaderlabs is using addtoany.com
+discussed in support tickets+relevant user stories