Google announced today at I/O that it is adding a new feature called Auto Awesome that combines photos together automatically to create new ones. It will link multiple images together to create a motion gif, for instance.
Another feature will combine multiple images together where some people are smiling and others are not to craft one good one where everyone is. HDR processing is also an option, as is automatic panoramic images from ones taken side by side.
These features are all completely automatic and done for you without any intervention. In fact, Gundotra says, Google has been going through your photos on Google+ and making a bunch of these for you automatically over the past few weeks.