Seems I set off a bit of an avalanche of feed reader switching (and lots of comments on the first post), so I thought I would post an update.
Short answer: it's working for me, and this is almost entirely due to how well the mobile mode works. I can now easily fit feed reading into a few spare moments. Starring items is how I mark them for followup.
I do have some issues / wishlist items for Google Reader...but rather than list them, I'll send you off to read Jame Healy, who has a great wishlist (and he just fell in love with Google Reader Mobile). I actually found a bit of a solution to the whole del.icio.us sharing issue: Gordita. That link, thanks to Bill Burcham, will create a bookmarklet for you that will let you bookmark items in del.icio.us from your Google Reader page. Now I can go through and bookmark all my starred items.
Alex Harford wants "oldest first" ordering.
gmail was pretty crappy for a week and a bit for me. Hard to sell me on the idea of an online life when service outages can just take everything away. At least with desktop tools I can see offline content.
If google or someone else could create an online store for feeds, and read vs unread items that I can synch from my desktop(s) that would be useful. On the road provide a nice UI. Perhaps google reader already does this. Don't know since I haven't checked it out.
As far as authenticated feed handling goes, I hope that if they add that feature, they handle it correctly. Some sites authenticate their feeds because it is a pay-for service. Google reader needs to consider the share feature in light of that.
Re: online only. With my new "business class" mobile phone (and, er, my grandfathered unlimited data Fido account), there are very limited places where I am truly "offline". I agree that more offline or synch services are warranted...but we're still in early days for feed reading in general. Troy Angrignon and Paul Kedrosky have some offline/online thoughts lately.
Your point about "sharing" of for-pay features is, I think, the same as for any other reader: I can easily re-post or otherwise share that content.
I actually was checking out the Gmail - Google Reader integration via a Greasemonkey script...but this won't work for me. I use mainly my "business" email which is Bryght's Gmail for Domains....but then it tries to use THAT version of my "identity" for Reader, as well. Hey, Google, did I mention you're STILL really screwed up about identity?
Lastly, I still need something on my desktop for authenticated feeds. I'm going to try out a few other readers to see if they fit this very specific task. My interaction with these feeds are primarily of the sort where it's *really* important whether or not I've actually read them...that is, more like a "to do" list rather than the information trawling I do with my main public feed subscriptions. On the list so far are NewsFire (not free, but gorgeous UI) and RSSOwl (free, open source, cross platform, and home page built with Drupal :P).