The Verge caught this little nugget on Yosemite:

You can remotely activate the personal hotspot feature on the iPhone and use it to connect your Mac to the internet…

I could honestly say that this is the feature that I appreciate the most. Connecting your Mac to your iPhone’s hotspot pre-iOS 8 was tricky to borderline annoying: if you miss the time window, the phone connects to a wifi forcing you to restart the whole process.