The new interface of blogger may take some time to become familiar with, but necessarily worth it. The old interface was not impressive, and it was making blogger look inferior than other blogging services like Wordpress, Tumblr etc. The new interface is definitely a welcome.
The feature is, I guess, only available to Blogger in draft users for now.
Also Gmail will soon getting a new interface. If you want to try, then activate the Preview or Preview(Dense) theme from the "Themes" tab in the Gmail settings page.