What they're launching today is a new reading mode called slider, and it is an optional alternative way to display articles from the feeds you follow. Rather than have the article appear in a window in the list of read and unread articles, you can now have the article pop out of the right side of the screen in a slider which looks like this:
The new reading mode is optional under the title and magazine viewing modes, but it is built in to the card viewing mode. You can turn it on or disable from the preferences menu.
Have you used it yet?
I've played with it for a few minutes, and it's growing on me. It looks very different from the service I'm using now, but I can see the value of Feedly's new design.
By placing the article in its own window, Feedly has made it easier for me to jump back from reading the article to sorting my feeds. I can see the list of articles at all times, so when I finish reading an article I will immediately know my location in the list and can continue to browse the list without concern that I might miss something.
It's a subtle change but a surprisingly useful one.