Lumen5 is a great tool I learned about from one of J. Wagner's tweets. It automatically creates a video in the form of a summary for a blog post. After you paste the url of your blog post, you choose the template you like. Then you click on the plus button to add content from the blog script that appears for you. You may need to edit the content you have added in each section by limiting it to 140 characters or by modifying it in the way you like. Here's an example of a Lumen5 video created from one of my blog posts.