Well, not really new, but a change.
read the GReaderBlog for more.
http://googlereader.blogspot.com/2006/06/careful-where-you-step-were-moving.html

Google Reader begins to look like gmail more. They might even get integrated... *-)

You can get a *form* of integration by creating a new label in reader (Eg. view-in-gmail), and adding it to all of your subscribed feeds (easy to do with the new reader update). Then just share this label and add it to your GMail webclips – presto!

It has just occured to me:

Do you think that this change could have been due to the appointment of that person (Douglas Bowman was it?) to maintain similar styles across Google Products.

The nes features of the UI are very Gmail/Calendaresque.