If you have TamperMonkey installed, this simple script should fix the problem:
// ==UserScript==
// @name SAHPA (Stack Apps Home Page Aligner)
// @namespace http://tampermonkey.net/
// @version 0.1
// @description Aligns the user names on the StackApps Home Page
// @author anonymous2
// @match http://stackapps.com/
// @grant GM_addStyle
// @run-at document-load
// ==/UserScript==
(function() {
'use strict';
for (i = 0; i < document.getElementsByClassName("summary").length; i++) {
document.getElementsByClassName("summary")[i].childNodes[3].childNodes[5].childNodes[3].setAttribute('style', "float:right;margin-top:5px;margin-right:7px;line-height:18px;color:#999");
}
})();
Not guaranteeing it's the most efficient way: still haven't found a way to reference those childNodes more directly, but it works. :)