Upgrading your Views from Drupal 6 to Drupal 7

Updating templates

If you have theme files for node-view-$viewname of comment-view-$viewname you have
to convert them to node--view--$viewname or comment--view--$viewname.

Updating table templates

The class variable was renamed to $classes. Additional if you want to add
classes, you should add it to $classes_array and drupal will automatically convert it to the $classes string.