I find that I am using LinkedIn less and less these days. It is an easy way to keep a contact list (the adding part, but I never use it to communicate with). Facebook does this better, so I think Facebook could completely replace them if they add ways to group your friends and allow you to control what you share at a group level.
It is a start, but it doesn't allow you to share say a link to HN for only your hacker/business peeps and a "the baby just did this" for your friends/family. As is, the HN link would just confuse my family (and maybe scare them) and nobody but my family wants to know that my boy just drove his car down the stairs.
