This is new to me. I noticed that my Google+ Circles collection had been extended. This is significant because until today all my Circles had been created by me.
The new Circle is called "Your YouTube subscriptions". It does what it says on the tin; it's a collection of all my YouTube subscriptions.
I rather like Google+ and as it happens this Circle turns out to be pretty useful. Just select it from "More" across the top menu, just next to "Mentions", and you have a clutter free way to scroll through the latest videos from the channels you're watching. Fewer ads, even.
In theory I could even put on alerts for when there's a new video in the Circle. That might be an effective to notice new content before other bloggers and curators do.