I've been trying to model libxml.js after Nokogiri. I wanted to get something built and working first. The next step is to expose libxml2's html parser.
Someone else has started working on find-by-CSS a la Nokogiri. I'll merge that into libxml.js when it's ready.
BTW, I'm looking for more help on this project. A new job has diminished the amount of time I can spend on OSS projects.