We're currently working on LinkedIn right now. When it's available, it will be a whole separate package that will obviously work with JFBConnect, but will be independent. There's a lot of differences between the two, and for support and development, they will need to be a separate subscription. However, we will have 'bundles' where if you subscribe to both, you can get a discount.
As for other networks, we're planning to add Google+ and Twitter as extensions in the future as well, but it will be a bit after LinkedIn becomes available, just to get feedback and make sure we don't go overboard. As for why we chose LinkedIn, it's simply simply because there are no competitors in Joomla for that, it's more business-y (which is a slightly different market than Facebook/Twitter/Google+), and it's more powerful than Twitter and more documented/stable than Google+..
Finally, with the upcoming 4.0 release of JFBConnect (next week), we'll be adding some social buttons, like Googe +1 and Twitter Share so that those can easily be added to content on your site. So, ideally, if you want just authentication within Facebook, but want additional social integration, hopefully JFBConnect will suit your needs.. but for more 'user' integration, the other extensions will be needed to add that flexibility.
Hope that all explains. Not sure what you mean by the "Nov attacks on Facebook"..
Thanks,
Alex
Future updates
