All In One SEO - Auto Complete Plugin

Is there such a tool or plugin available that will automatically fill in the title, description (possible scrape the first 2/3 lines of each post) & keywords fields from already existent posts?

I thinking from an autoblog perspective that you could have such a plugin or tool complete this section for all posts which already exist and then complete this information on the new posts that automatically get posted to your blog.

So you would install the plugin and it would go out and analyze your posts and complete these 3 fields or alternatively you could tell the plugin what you want these fields to have in them (possibly with spun text) on a category basis.

With autoblogs these get left blank so if you optimizes them with category relevant content then it should help... Right??

Is there already such a tool or is this at all possible?

Platinum SEO does all of that except it's a bit iffy on the keywords. It can generate keywords by using tags and categories as additional meta keywords, but it unfortunately doesn't analyze the post for more. This works with old posts too.