I'm attempting to find time to assist with it, but haven't thus far. Perhaps throwing it out here will bring in additional assistance
YSlow is pretty useful, both as a developer and when attempting to demonstrate potential problems with a site's performance to others in an objective way.
Besides: a plugin with its own plugins is just cool.
So while this is "on the road" to being fixed, it's not fixed completely.
And I'm not sure what you mean about the source. I see the correct source when I debug evaled scripts in Firefox Nightly.
I honestly wish they did since there are very few features I would miss from Firebug itself but the plugins add very useful features.