Layout tabs are enhanced to include a new plus (+) icon for quickly adding new layouts. A tooltip displays the layout name in addition to the preview image when you pass the cursor over a Layout tab. An overflow menu provides easy access to layouts when they extend beyond the width of the display.
The appearance of layout sheets has been updated and a new color option, accessible from the Colors button on the Display tab of the Options dialog box, enables you to control the paper background color.
Check out the AutoCAD 2015: User Interface video to see the enhanced Layout tabs in action along with many other UI improvements.