Index: wp-admin/includes/class-wp-theme-install-list-table.php
===================================================================
--- wp-admin/includes/class-wp-theme-install-list-table.php	(revision 19878)
+++ wp-admin/includes/class-wp-theme-install-list-table.php	(working copy)
@@ -9,6 +9,12 @@
  */
 class WP_Theme_Install_List_Table extends WP_List_Table {
 
+	function __construct() {
+		parent::__construct( array(
+			'ajax' => true,
+		) );
+	}
+
 	function ajax_user_can() {
 		return current_user_can('install_themes');
 	}
@@ -128,7 +134,7 @@
 
 	function display() {
 
-		// wp_nonce_field( "fetch-list-" . get_class( $this ), '_ajax_fetch_list_nonce' );
+		wp_nonce_field( "fetch-list-" . get_class( $this ), '_ajax_fetch_list_nonce' );
 ?>
 		<div class="tablenav top themes">
 			<div class="alignleft actions">
Index: wp-admin/includes/class-wp-themes-list-table.php
===================================================================
--- wp-admin/includes/class-wp-themes-list-table.php	(revision 19878)
+++ wp-admin/includes/class-wp-themes-list-table.php	(working copy)
@@ -11,6 +11,12 @@
 
 	var $search = array();
 	var $features = array();
+	
+	function __construct() {
+		parent::__construct( array(
+			'ajax' => true,
+		) );
+	}
 
 	function ajax_user_can() {
 		// Do not check edit_theme_options here. AJAX calls for available themes require switch_themes.
@@ -47,7 +53,7 @@
 		unset( $themes[$ct->name] );
 		uksort( $themes, "strnatcasecmp" );
 
-		$per_page = 24;
+		$per_page = 999;
 		$page = $this->get_pagenum();
 
 		$start = ( $page - 1 ) * $per_page;
@@ -101,7 +107,7 @@
 	}
 
 	function display() {
-		// wp_nonce_field( "fetch-list-" . get_class( $this ), '_ajax_fetch_list_nonce' );
+		wp_nonce_field( "fetch-list-" . get_class( $this ), '_ajax_fetch_list_nonce' );
 ?>
 		<?php $this->tablenav( 'top' ); ?>
 
Index: wp-admin/js/theme.dev.js
===================================================================
--- wp-admin/js/theme.dev.js	(revision 19878)
+++ wp-admin/js/theme.dev.js	(working copy)
@@ -53,3 +53,174 @@
 	theme_viewer = new ThemeViewer();
 	theme_viewer.init();
 });
+
+var wpThemes;
+
+(function($){
+	var inputs = {}, Query;
+
+	wpThemes = {
+		timeToTriggerQuery: 150,
+		minQueryAJAXDuration: 200,
+		outListBottomThreshold: 200,
+		noMoreResults: false,
+		
+		init : function() {
+			$('.pagination-links').hide();
+
+			inputs.nonce = $('#_ajax_fetch_list_nonce').val();
+	
+			// Parse Query
+			inputs.queryString = window.location.search;			
+			inputs.queryArray = wpThemes.parseQuery( inputs.queryString.substring( 1 ) );
+
+			// Handle Inputs from Query
+			inputs.search = inputs.queryArray['s'];
+			inputs.features = inputs.queryArray['features'];
+			inputs.startPage = parseInt( inputs.queryArray['paged'] );	
+			inputs.tab = inputs.queryArray['tab'];
+			inputs.type = inputs.queryArray['type'];
+
+			if ( isNaN( inputs.startPage ) )
+				inputs.startPage = 2;
+			else
+				inputs.startPage++;
+
+			// Cache jQuery objects
+			inputs.outList = $('#availablethemes');
+			inputs.waiting = $('div.tablenav.bottom').children( 'img.ajax-loading' );
+			inputs.window = $(window);
+
+			// Generate Query
+			wpThemes.query = new Query();
+
+			// Start Polling
+			inputs.window.scroll( function(){ wpThemes.maybeLoad(); } );
+		},
+		delayedCallback : function( func, delay ) {
+			var timeoutTriggered, funcTriggered, funcArgs, funcContext;
+
+			if ( ! delay )
+				return func;
+
+			setTimeout( function() {
+				if ( funcTriggered )
+					return func.apply( funcContext, funcArgs );
+				// Otherwise, wait.
+				timeoutTriggered = true;
+			}, delay);
+
+			return function() {
+				if ( timeoutTriggered )
+					return func.apply( this, arguments );
+				// Otherwise, wait.
+				funcArgs = arguments;
+				funcContext = this;
+				funcTriggered = true;
+			};
+		},
+		ajax: function( callback ) {
+			var self = this,
+				response = wpThemes.delayedCallback( function( results, params ) {
+					self.process( results, params );
+					if ( callback )
+						callback( results, params );
+				}, wpThemes.minQueryAJAXDuration );
+
+			this.query.ajax( response );
+		},
+		process: function( results, params ) {
+			// If no Results, for now, mark as no Matches, and bail.
+			// Alternately: inputs.outList.append(wpThemesL10n.noMatchesFound);
+			if ( ( results === undefined ) ||
+				 ( results.rows.indexOf( "no-items" ) != -1 ) ) {
+				this.noMoreResults = true;
+			} else {
+				inputs.outList.append( results.rows );
+			}
+		},
+		maybeLoad: function() {
+			var self = this,
+				el = $(document),
+				bottom = el.scrollTop() + inputs.window.innerHeight();
+				
+			if ( this.noMoreResults ||
+				 !this.query.ready() || 
+				 ( bottom < inputs.outList.height() - wpThemes.outListBottomThreshold ) )
+				return;
+
+			setTimeout( function() {
+				var newTop = el.scrollTop(),
+					newBottom = newTop + inputs.window.innerHeight();
+
+				if ( !self.query.ready() ||
+					 ( newBottom < inputs.outList.height() - wpThemes.outListBottomThreshold ) )
+					return;
+
+				inputs.waiting.css( 'visibility', 'visible' ); // Show Spinner
+				self.ajax( function() { inputs.waiting.css( 'visibility', 'hidden' ) } ); // Hide Spinner
+				
+			}, wpThemes.timeToTriggerQuery );
+		},
+		parseQuery: function( query ) {
+			var Params = {};
+			if ( ! query ) {return Params;}// return empty object
+			var Pairs = query.split(/[;&]/);
+			for ( var i = 0; i < Pairs.length; i++ ) {
+				var KeyVal = Pairs[i].split('=');
+				if ( ! KeyVal || KeyVal.length != 2 ) {continue;}
+				var key = unescape( KeyVal[0] );
+				var val = unescape( KeyVal[1] );
+				val = val.replace(/\+/g, ' ');
+				key = key.replace(/\[.*\]$/g, '');
+	
+				if ( Params[key] === undefined ) {
+					Params[key] = val;
+				} else {
+					var oldVal = Params[key];
+					if ( ! jQuery.isArray( Params[key] ) )
+						Params[key] = new Array( oldVal, val );
+					else
+						Params[key].push( val );
+				}
+			}
+			return Params;
+		}
+	}
+
+	Query = function() {
+		this.failedRequest = false;
+		this.querying = false;
+		this.page = inputs.startPage;
+	}
+	
+	$.extend( Query.prototype, {
+		ready: function() {
+			return !( this.querying || this.failedRequest );
+		},
+		ajax: function( callback ) {
+			var self = this,
+			query = {
+				action: 'fetch-list',
+				tab: inputs.tab,
+				paged: this.page,
+				s: inputs.search,
+				type: inputs.type,
+				_ajax_fetch_list_nonce: inputs.nonce,
+				'features[]': inputs.features,
+				'list_args': list_args
+			};
+
+			this.querying = true;
+			$.get( ajaxurl, query, function(r) {
+				self.page++;
+				self.querying = false;
+				self.failedRequest = !r;
+				callback( r, query );
+			}, "json" );
+		}
+	});
+
+	$(document).ready( wpThemes.init );
+
+})(jQuery);
Index: wp-admin/theme-install.php
===================================================================
--- wp-admin/theme-install.php	(revision 19878)
+++ wp-admin/theme-install.php	(working copy)
@@ -33,6 +33,7 @@
 
 add_thickbox();
 wp_enqueue_script( 'theme-preview' );
+wp_enqueue_script( 'theme' );
 
 $body_id = $tab;