After some developers did some digging into the latest Google+ apk, they found some intriguing new possibilities for future features. Embedded were some some image files for Google’s Chromecast icon. Could this mean Google is planning on bringing Chromecast support to Google+? It seems likely. This basically means sometime in the future we might just see casting come to Google+ content. It's possible at first that this will just be videos, Hangouts video calls, etc., but that's a great start.
Obviously the presence of these icons doesn't give us a clue as to when (or even if) this feature will show up. Still, to see this in the apk now suggests it is something they are working on, so there's a remote possibility we could see something this year. We will keep an eye out for it!
Source: Google+