Hey there, this plugin works great with the latest version of WordPress. It did exactly what it was supposed to do.
However, I have a suggestion for a future version. The top images on all my posts are resized versions of images that I uploaded, meaning that if the original image is called photo.jpg, the top images have names like photo-600x400.jpg. In the process of creating thumbnails, the plugin created an extra entry in the media list for every post -- now the media lists contain both a photo.jpg and a photo-600x400.jpg, when one is an exact replica of the other. It didn't add any new images to my uploaded media folder, because all the photo-600x400.jpg files were already there as versions of photo.jpg.
My only complaint is that it's sloppy -- would there be any way for a later version to recognize when the top image is a resized version of an image that's already in the media folder?