Registers a [public_attendee_list] shortcode. Should work with The Events Calendar + WooCommerce Tickets (or any of the other related ticketing addons). Simply drop the shortcode into the event description and it will *publicly* list how many folks are attending etc... tweak to make it fit your own needs! You may for instance wish to add a check…

public_attendee_list.php

<?php
/**
 * Generates output for the [public_attendee_list] shortcode.
 *
 * Assumes we're interested in the current event or, optionally, a specific
 * event ID can be provided:
 *
 *     [public_attendee_list id="789"]
 *
 * This is a rudimentary starting point only! Please assess and tweak to
 * fit your own needs.
 *
 * @param  $params
 * @return string
 */
function build_public_attendee_list( $params ) {
	// Which event are we interested in?
	if ( is_array( $params ) && isset( $params['id'] ) ) $id = absint( $params['id'] );
	else $id = get_the_ID();

	// Is it truly an event?
	if ( TribeEvents::POSTTYPE !== get_post_type( $id ) )
		return '<p> Unable to display attendee list: this does not seem to be a valid event. </p>';

	// Get the attendees
	$attendees = TribeEventsTickets::get_event_attendees( $id );

	// Perhaps no one is attending
	if ( empty( $attendees ) )
		return '<p> No confirmed attendees just yet. </p>';

	// Form a report of any known attendees
	$report = '<p>' . count( $attendees ) . ' confirmed attendees: </p> <ul>';

	foreach ( $attendees as $attending ) {
		$name  = esc_html( $attending['purchaser_name'] );
		$order = esc_html( $attending['order_id'] );
		$report .= "<li> $name (#$order) </li>";
	}

	return $report . '</ul>';
}

// Register our new [public_attendee_list] shortcode
add_shortcode( 'public_attendee_list', 'build_public_attendee_list' );

Quick use: add to your theme's functions.php file (but remember that, typically, you will need to remove the leading <?php tag before doing this).