Metadata has been around in one form or another for a long time, but in many ways it's still in its infancy. Having a standard in the form of XMP is one factor that will doubtless accelerate its evolution, and the ready availability of basic shooting parameters from the EXIF data is another.
Today, photographers can gain a considerable measure of security by knowing that their copyright and rights management notices are embedded right in the image. In the future, you can reasonably expect to see software that makes more intelligent use of metadataautomatically applying the right lens corrections based on focal length, or the right noise reduction based on ISO speed, for example. You can also look forward to seamless integration with XMP-compliant asset managers and databases.
You'll doubtless encounter speed bumps along the way, but if you understand how image metadata works, you'll be in a much better position to troubleshoot any problems you encounter than those who just treat the whole thing as incomprehensible magic. I hope this chapter provides a starting point for further metadata explorations.