You can use get_post_type
add_filter('excerpt_more', 'new_excerpt_more');
function new_excerpt_more($more) {
global $post;
$post_type = get_post_type($post);
switch( $post_type ):
case 'event':
$teaser="<a class="moretag" href="". get_permalink($post->ID) . '"> More events </a>';
break;
case 'post':
$teaser="<a class="moretag" href="". get_permalink($post->ID) . '"> … </a>';
break;
default
$teaser="";
endswitch;
return $teaser;
}