As much as I like the Google+ interface (its clean, presents content really nicely and looks pretty fresh), Google still hasn’t figured out how to present shared posts in an efficient way. Shared posts tend to look a lot like this:

Shared post display - Google Plus

On the other hand, Facebook handles shared posts far better:

Shared post display - Facebook

The Facebook method makes a lot more sense and means we’re unlikely to have a stream cluttered with multiple instances of the same content items.