My tools are usually Photoshop and Exif Pilot and I know how to export to XMP and import, but I was told that the full Exif data does not copy from one image to another. Is this true? This is my Exif view in Photoshop, there is also IPTC which I think is just another metadata flavor.
Adding my intent in posting this, it's also about the relation between Exif data and images being found with image search on Google.
Matt Cutts regarding Exif for Google Image search:
Does Google use any of this information as a ranking factor? Matt says Google reserves the right to use EXIF data in order to help people find information about an image. In a previous version of image search, Google used to show this information in a sidebar when it was available.