I've been working on a photography related website and was investigating how to include EXIF data with images. It seems that WP reads a portion of the EXIF data when an image is imported, stores the data in the WP database and then strips all EXIF and IPTC from the image and stores that on the webserver.
This prevents, for example, using the PHP function exif_read_data to extract additional pieces of EXIF or IPTC data from the image file. Of course, this is also why there are no plugins that do this sort of thing either (the exception being the Exifography plugin, but it only supports the importing of a handful of additional EXIF fields and isn't easily extended to include more by the user).
From a photographers standpoint, this is REALLY BAD for two reasons:
1) it removes the EXIF data that contains a copyright notice, author information, etc. from the image itself.
2) it makes it very difficult (impossible unless you know PHP and are willing to hack WP core files) to import additional EXIF fields or other metadata such as IPTC.
Now I realize that the EXIF data can be easily changed so it isn't a fool-proof method of indicating copyright and/or authorship for an image but what is the harm in retaining this information? If striping it out serves a purpose, I would like to suggest that this be made optional behavior for WP as I, for one, would like the EXIF and other meta-data to be retained.