Drupal's core RSS handling adds a link to each taxonomy term's page using the optional "domain" attribute on category tags. The attached patch adds support for this behavior by modifying the category preprocessor to recognize links. To use it with a view, configure the Taxonomy field with "Link this field to its term page" checked.
The patch also modifies views_rss_htmlspecialchars to handle multiple elements, which was necessary so that it could be moved to run after the category preprocessor.
A secondary benefit of this patch is that terms with commas will be parsed correctly. Currently, terms with commas get broken apart.