Also: star, like, share, tag. Those are too many options. Give me a +1 and a "Share" button and I'm set.
I thought this discussion needed a thread that wasn't all "I hate change".
Tagging is very different from sharing or liking. It's a feature for organizing specific items (aka posts) for yourself, not for others.
Though there are sharing options in Reader, it's largely been useless for me, and the same few people who followed me (or I followed) are on G+ now.