By default, a Drupal 7 image field that is set to contain multiple images, will display all of the images in both the teaser and full node view. While desirable, there is no option when creating a view to only show the first image in the teaser. This can be accomplished, however, with the new Drupal 7 field-level template-hint.
In order do this globally for a field named "field image" the following code in a template file named "field--field_image.tpl.php"
<div class="<?php print $classes; ?> clearfix"<?php print $attributes; ?>>