Eoin,
Glad you like the new site.. I think. Would love your feedback on any confusion, problems or general points you'd like to point out on it. In general, we love it over the old site.. but after staring at the old one every day for 5'ish years.. well, you can get tired of anything like that.
Regarding JLinked, the extension itself will be discontinued, but all of the features of it will be rolled into our Facebook/JFBConnect extension. JFBConnect actually has more underlying features than JLinked, so integrating those LinkedIn features will actually add more features to LinkedIn.. in addition to the ability to use Facebook, Google, and Twitter functions that will be available at that time.
It will be very possible to disable any social network login/integration features from the 'new' JFBConnect when those extra social networks are implemented.. Boiling it down, if you like JLinked, you'll have all the same abilities with JFBConnect, but things should actually work better.
When JLinked is extinct-ified, we will still be supporting it for some time going forward with bug-fixes as necessary. We'll also have an automatic migrator that will move your settings from JLinked over to JFBConnect. Ideally, the switch will be a matter of uninstalling JLinked and installing the new version of JFBConnect.
I hope that helps explain, but certainly if you have any questions, just let me know. We intentionally wanted to give heads up to our JLinked users specifically so these types of questions could be raised ahead of time and plans could be made (though not much planning should be necessary if we do our job right).
Thanks,
Alex