I’m a new user to wordpress myself, but I just solved a similar issue using an iframe. iframe works in this instance because it points to a completely unique html/php file with its own headers. This means, for your particular case, you can include the header for your blog installation without conflict when it’s displayed on a wpdev wordpress page.
Here are the steps to make this work.
1. Create a unique php page (blog_widget.php) that points to the blog header and displays the content you want and save it in the wpdev directory. It will look something like this:
<!DOCTYPE html>
<!-- paulirish.com/2008/conditional-stylesheets-vs-css-hacks-answer-neither/ -->
<!--[if lt IE 7 ]> <html class="ie6" lang="en"> <![endif]-->
<!--[if IE 7 ]> <html class="ie7" lang="en"> <![endif]-->
<!--[if IE 8 ]> <html class="ie8" lang="en"> <![endif]-->
<!--[if (gte IE 9)|!(IE)]><!--> <html lang="en"> <!--<![endif]-->
<head>
<meta charset="utf-8" />
<title></title>
<!-- Include Word Press Head Files -->
<?php require('../blog/wp-blog-header.php'); ?>
</head>
<body>
<?php query_posts('showposts=3'); ?>
<?php while (have_posts()) : the_post(); ?>
<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a><br />
<?php endwhile;?>
</body>
</html>
2. Then, on the page that you actually want to display the information, you load the php page you just created by using an iframe. For example:
<iframe src="blog_widget.php" width="100%" scrolling="no">
<a href="../blog" title="Alt link to Blog for non-iframe browsers">Blog</a>
</iframe>
Hope this helps!
