Bloglines has actually been working on their user interface recently. They have two new features, Playlists and Glimpses. Playlists look to be lightweight groupings of feeds and Glimpses give you quick, tooltip style, overviews of Playlists. I'm not sure how much of a UI advance this actually is, but the features are welcome experimentation in feed aggregators.
The irony is that I read the notice of Playlists and Glimpses in Google Reader, which is starting to grow on me. I'm feeling like my Bloglines days are numbered, but the jury is still out.