Google is rolling out Android Wear 5.0.2 update to select Android Wear devices. First it was the Moto 360 and the list includes the Samsung Gear Live and the LG G Watch R.
The update doesn't seem to add any new features; according to Motorola's changelog, all it brings is an updated version of Google Play services and a variety of optimizations and security updates.
If you have any of these devices, you should be getting the notification to update any time now. Other Android Wear devices will have to wait for some time.