The VM integration we have right now is completely for authentication. A user can register and login using any of the social networks we support. When they come from a social network, their VM user profile will be automatically filled out, which improves their cart -> checkout time by not having them have to create a username, password, fill out their name, fill in their city, state, and country, etc. There are many different fields from each network that can be imported, and it's up to you how to import them.
Additional things that can be done, but not automatically, is adding the social widgets (Like, Comments, Share buttons, etc) to your VM pages. We have lots of easy tools to help add social features to any content on your site, not just VM.
We do have future plans for deeper Open Graph, posting, and other features, but I don't have a timeline on when those features would be implemented.
I hope that helps explain, but should you have any other questions, just let me know.
Thanks,
Alex