Adobe pulled back the curtain on a new feature that will make its way into Photoshop soon. It’s called Content-Aware Crop and it’s able to automatically and intelligently fill in pixels around blank spaces when you expand or rotate an image.
According to Adobe, you’ll be able to use the new tool to move the horizon by adding more sky or ground, change the aspect ratio of an image by adding content around the edges and fill in the corners when you rotate an image so you don’t give up any of your pixels.
There’s no firm word yet on when you Content-Aware Crop will pop up in Photoshop CC, but there is this video giving you a bit more insight into how it should work when it does. Looks very promising.