This is actually a copy of (for d5):
http://drupal.org/node/197967
But the link of "Bèr Kessels" http://drupal.org/node/197967#comment-651386 seems dead.

Please add "first" and "last" css classes to lists of tags.
The default list of taxonomy terms in Drupal does the same. This allows more flexible theming.

Using the views implementation resulted in putting the request here,
but this also applies for the tagadelic module having no first and last css.
http://drupal.org/project/tagadelic.