Just upgraded from 2.7.1 to 2.8.1 and notice some of my favorite and most used functions were missing. The 'Post updated. Continue editing below or go back.' notice at the top of the post or page after you edited and saved is no longer there. This was an extremely helpful link if you are make a number of changes to pages or posts listed on pages 4 or 5 of your list of pages or posts.
Without the go back link, if you have changes to make on two or more pages listed on page 4 of the list of pages, after you make the change to the first page, you have to go back to the list of pages, click on pg 3, and then click on page 4 before you can then find the page you actually want to edit. With the go back link you hit the link and you're taken right back to the spot you were at on page 4.
I'm also missing the comments made on a specific post being listed at the bottom of that posts edit page. It was very nice to be able to go to the edit page of any post and see any pending comments there at the bottom of the page, rather than having to scroll through several pages of comments, looking for comments to a specific post.
Other than that, I'm really enjoying the new 2.8.1 version.