del.js

// ==UserScript==
// @name           DeletedSubmissions
// @namespace      com.md_5
// @description    Hide those pesky deleted Bukkit submissions
// @include        http://forums.bukkit.org/forums/plugin-submissions.20/*
// ==/UserScript==

var threadHolders = document.getElementsByClassName("discussionListItems");
for (var i = 0; i < threadHolders.length; i++) {
	var deletedThreads = document.getElementsByClassName("discussionListItem deleted");
	for (var j = 0; j < deletedThreads.length; j++) {
		threadHolders[i].removeChild(deletedThreads[j]);
	}
}