I'm not sure what the status is of the GHRML bit as I only recently was looking into it. Can't find a repo for it, original developer doesn't have time for it anymore and maintenance was picked up by someone else with an interest in the project. Any extra info on this would be helpful.
Unfortunately, as these things go, I started writing my own HAML style processor ;)
http://dasacc22.wordpress.com/2010/05/03/python-implementation-of-haml/
It's in no way fit for production use at the moment (its literally a 4 day old infant now but like 60+hours crammed in those 4 days) but anyone interested may check it out here. It has a range of features already implemented that make it useful as a toy, and as I clean up the codebase over the next week, I hope to see it replace all my custom XSLT/xpath extensions and templates I have.