Just read the latest blog entry from LinkedIn called New: Get Notified on LinkedIn. To summarize quickly (because I've got to leave for a lunch meeting!) they are going to make it easier for users to see when "...someone likes what you've shared on LinkedIn, views your profile, accepts your invitations, and much more."
Looks like this change is live, for me at least, because I can see a change at the top of my LinkedIn page. LinkedIn sometimes rolls out changes slowly, but the post doesn't say so, so I'm guessing it is live for everyone.
I like hearing this, because certain notifications have been hard to track down. Number one has been when someone likes something you've posted - I've sometimes had a hard time finding out who it was, short of liking it myself.
The post concludes by promising updates to the mobile apps.
Now I have one less future blog post topic, because I was going to say something that some of this information is hard to find. But I'm ok with that!
UPDATE: This feature is definitely working for me. All of the sudden I've got 19 notifications on various people liking updates and other activity. Had no idea. Also some stuff liked by people I don't know. Have to investigate.