This has been available in beta for some number of months, and it's been a much better experience than the original Steam family sharing setup, where you essentially shared the entire library instead of individual games.
With Family Sharing, if one of your family members was playing a game from your library, and you started playing some other completely unrelated game, then you'd boot them from their current game. This makes some sense if you think about this from the perspective of sharing a console, but not so much if you handed them a physical disk to play on their own console.
With Steam Families, you only kick the person off if they're playing the same game that you want to. (And of course, you can still have multiple copies of the same game in the family library, in which case you only evict someone if there are no more copies available. Or I guess if they're explicitly playing your copy for, say, DLC that you own.)
Ohh, finally. I’ve been playing with Steam "offline" for quite some time now (only singleplayer, so it doesn’t matter) so I don’t kick my wife out of whatever she is playing from my library. This is awesome.
With Family Sharing, if one of your family members was playing a game from your library, and you started playing some other completely unrelated game, then you'd boot them from their current game. This makes some sense if you think about this from the perspective of sharing a console, but not so much if you handed them a physical disk to play on their own console.
With Steam Families, you only kick the person off if they're playing the same game that you want to. (And of course, you can still have multiple copies of the same game in the family library, in which case you only evict someone if there are no more copies available. Or I guess if they're explicitly playing your copy for, say, DLC that you own.)