This is really cool & solves a problem for me. I installed the bookmarklet and am looking forward to using it. I see that you are relying on the community to summarize pages & don't have a large enough data set built up yet.

What would be awesome is if you could somehow automate summarization using NLP. Check out condensr.com. They are able to summarize restaurant reviews...might not be at the same quality level as your current summaries but it came out of research from MIT & could be useful to you.