Tim,
I have written "Please don't forget, themes are for themers and not for programers." What is unclear with this sentence?
I have written several times about the designer's needs here in the forums. Themers or designers are skilled in XHTML. When we can set up the whole XHTML structure, we can much more flexible react on different needs. When Moodle outputs the header inclusively body tag we need to program to include changes.
Please try not to be restricted in your developer thinking. Try to understand designer thinking when you create a part of Moodle which is mainly used by designers.
And when you may decide to go your developer way please write a good and easy to understand documentation how we can override the Moodle core method creating the header to output the header as I posted. That would create more cost on our side to create the extra code but is better than the need to be forced to hack around in 2.0 as it is needed in 1.9 themes.