Google Reader simplified the commenting feature so that anyone can comment on a shared item. "To make things a lot simpler, we've made it so that if you can see a shared item, you can comment on it." An important effect is that Google Buzz users can comment on any post shared in Google Reader, assuming that shared items are connected to a Buzz profile. Since you can now comment on a Google Buzz post by replying to a message in Gmail, you could share a blog post in Google Reader and one of your Buzz followers could post a comment from in Google Buzz and then reply to your answer from Outlook, Thunderbird or from the Gmail mobile app for Blackberry.
If you don't like Google Reader's interface, there're desktop apps like FeedDemon, NetNewsWire or Liferea that import your GR subscriptions and synchronize your actions with Reader. That means you could share a blog post in FeedDemon and someone could post a comment from Google Buzz or from an app that uses Google Buzz API.
Also, Google Reader will drop support for outdated browsers (IE6, Firefox < 3.0, Safari < 4.0, Chrome < 4.0) and will remove offline mode powered by Google Gears starting on June 1.