Hi McNaz. One great feature of 0.5 is it's new debug mode, which makes it a whole lot easier to understand what's happening with xajax. It also allows customized plugins.
Here's something i figured out today:
When using xajax you have to set your output code to a specified var then use that to be placed in a div (or p or whatever you prefer):
 $text = "Hello World!"; 
$objResponse->assign("div1","innerHTML",$text);  
In this case $text will be placed inside "div1". My problem was that I couldn't use $xoopsTpl->display because this would start outputing code before xajax started it's process. This is a big NO-NO for xajax and halt's it's execution. Now I could do something like this:
 ////////////////////////////////////////// 
    // set template for xajax response 
    ob_start(); 
include(XOOPS_ROOT_PATH.'/modules/kshop/templates/xajax/assignby.php'); 
    $text = ob_get_contents(); 
    ob_end_clean(); 
        $objResponse->assign("div1","innerHTML",$text); 
///////////////////////////////////////////  
Now this would get properly processed and placed into "div1". but the problem is I can NOT use standard smarty code such as <{$xoops_url}> with this method.
Today, while reading Smarty.class.php I finally solved this:
 $text = $xoopsTpl->fetch('db:admin_smartytest.html', null, null,FALSE); 
$objResponse->assign("div1","innerHTML",$text);  
This will now grab the template from DB, process all it's smarty code then place it inside "div1". This is a great method for placing xajax code inside XOOPS blocks.
Since i was so happy solving this problem, I decided to share my solution 
