Well, I think it's pretty nifty, sort of carries the torch for (the
pretty much stale) Google Notebook, etc., but there are two things
that I would find vastly more useful for actual feed reading than
annotated sharing:

1) Filtering

PLEASE add filtering of some sort to Google Reader - I am now doing my
own Bayesian filtering of stuff outside of it and hacking stuff
together with Yahoo Pipes, and it's vastly more efficient than Reader
by itself.

2) Accepting and propagating tags as <category> fields in RSS/Atom

The current tagging mechanism is useless if you want to integrate it
with anything else - not only does Google Reader not respect incoming
tags in RSS feeds, it also does not propagate tags on shared/public
feeds.

If these two things were fixed, tagging/annotating and sharing would
be much more efficient in many regards.

Until they aren't, well, I'll try to work around them as is.

For further reading:

http://the.taoofmac.com/space/blog/2008/01/27/2203

Regards,

R.