Images are the one of the oldest items on the web (right after HTML) and still so little has changed since we started to use them. That's if you don't count lots of creative talent that went into creating them, so much in fact that it created the web as we know now, rich, shiny and full of marketing potential.
That being said, images on our websites are the largest payload shifted back and forth across the wires of the net taking big part in slowing down pages. Still we can safely assume that we are going to have only more images and they will only grow bigger, along with the screen resolutions on user computers.
If you want to stop slowing down your pages and reducing user experience, it's time to take images seriously and implement image processing pipeline within your organization!