Instead of one long window holding all the posts you now have a smaller window holding only some of the posts, with buttons at the bottom to go to older or newer posts. You also have a panel at the side through which you can home in on posts for a specific month.
There's also a Followers panel. I don't really understand that bit.
This change results from Google's introduction of the Layouts system for its blogs. If you know about all this let me know of any thoughts you have for changes or improvements.
Best wishes, Seamus