A Skeleton

gistfile1.aw

<?php
class MostDiscussed_Widget extends WP_Widget {

	private $excluded_posts;

	function __construct() {

	}

	function widget( $args, $instance ) {
		$excluded_posts = get_transient( 'consumerist_most_discussed_exclude' );

		if ( false === $excluded_posts )
			$excluded_posts = $this->generate_most_discussed_excluded_posts();

		$pop_query = get_transient( 'consumerist_most_discussed_exclude' );

		if ( false === $pop_query )
			$pop_query = $this->generate_most_discussed_query();

		// Get your loop on
	}

	function update( $new_instance, $old_instance ) {
		// Do the normal validation
		$this->generate_most_discussed_excluded_posts();
		$this->generate_most_discussed_query();

		return $instance;
	}

	function form( $instance ) {

	}

	function generate_most_discussed_excluded_posts() {
		// Query for the excluded posts and save to transient

		$excluded_posts = wp_list_pluck( $excluded_posts->posts, 'ID' );

		set_transient( 'consumerist_most_discussed_exclude', $excluded_posts ); // no expiration
		$this->excluded_posts = $excluded_posts;

		return $excluded_posts;
	}

	function generate_most_discussed_query() {
		// Query for most discussed posts and save to transient
		set_transient( 'consumerist_most_discussed', $pop_query ); // no expiration

		return $pop_query;
	}

	function filter_most_discussed( $where = '' ) {

	}
}