Google Reader has gained "Liking" posts, which is great and what I thought "Sharing" should have done all along. I.e. I've always thought that if I've shared a post I should be able to see who else has shared it. And that is precisely what "Liking" does.
I don't know if you can combine the two (share and like at the same time) as I haven't been able to "Like" anything yet as it's not available on the mobile view. At least as far as I can tell.
The only bad news with this is that it comes just after Jon Hick's stopped work on Helvetireader.