Totally agree with +Joel Mackey
on this one. Saw several shares duplicated shares today, each with their own set of comments. To have those aggregated in some way would be awesome.
I have started watching the number of shares at the bottom of each post, and if I see a few of my friends have already shared a post, I simply comment instead of sharing. Maybe if Google made this more prominent, people would think twice before sharing again in their circles?
I have also noticed many people doing "via type" reshares to credit several users for the share, and that has the possibility of being really spammy. Not only are they creating a new post, it's also basically hijacking the original share. I personally like that the original poster now gets the credit for the share, and feel that commenting on most shares may be the best option on Google+.
Maybe instead of sharing, google+ could allow comments to also show as a post in your feed, with a link and title of the post? This would allow a link to the post, and your comments visible to your circles, but not a full reshare. ;-)
cc: +Jonathan Lally +Dave Besbris