converted customButton plugin to widget factory (note: this is just the plugin for native button elements, not to be confused with the buttonMarkup plugin).

renamed method to "button" and updated page.js to match

js/jquery.mobile.forms.button.js

@@ -4,23 +4,36 @@
 * Dual licensed under the MIT (MIT-LICENSE.txt) and GPL (GPL-LICENSE.txt) licenses.
 * Note: Code is in draft form and is subject to change 
 */ 
-(function($){
-$.fn.customButton = function(){
-	return $(this).each(function(){	
-		var button = $(this).addClass('ui-btn-hidden').attr('tabindex','-1');
+(function ( $ ) {
+$.widget( "mobile.button", $.mobile.widget, {
+	options: {},
+	_create: function(){
+		var $el = this.element;
+			$el
+				.addClass('ui-btn-hidden')
+				.attr('tabindex','-1');
+		
 		//add ARIA role
-		$('<a href="#" role="button">'+ (button.text() || button.val()) +'</a>')
-			.buttonMarkup({
-				theme: button.data('theme'), 
-				icon: button.data('icon'),
-				iconpos: button.data('iconpos'),
-				inline: button.data('inline')
-			})
+		$( "<a>", { 
+				"href": "#",
+				"role": "button",
+				"aria-label": $el.attr( "type" ) 
+			} )
+			.text( $el.text() || $el.val() )
+			.insertBefore( $el )
 			.click(function(){
-				button.click(); 
+				$el.click(); 
 				return false;
 			})
-			.insertBefore(button);
-	});
-};
-})(jQuery);
+			.buttonMarkup({
+				theme: $el.data("theme"), 
+				icon: $el.data("icon"),
+				iconpos: $el.data("iconpos"),
+				inline: $el.data("inline"),
+				corners: $el.data("corners"),
+				shadow: $el.data("shadow"),
+				iconshadow: $el.data("icon-shadow")
+			});
+	}
+});
+})( jQuery );

js/jquery.mobile.page.js

@@ -132,7 +132,7 @@ jQuery.widget( "mobile.page", jQuery.mobile.widget, {
 		this.element
 			.find( "button, [type='button'], [type='submit'], [type='reset'], [type='image']" )
 			.not( ".ui-nojs" )
-			.customButton();
+			.button();
 
 		this.element
 			.find( "input, textarea" )