Not to be a troll but how much of that is patented by Yahoo? If its recent threat to sue Facebook is any indication, "Methods to reduce HTTP requests" could be one of its patents that it's willing to wield.
Btw, like someone just pointed out - YSlow (A tool that has all these rules) was just open sourced under the BSD license by Yahoo! - http://developer.yahoo.com/blogs/ydn/posts/2012/02/welcome-y...