FYI - for those of you looking for a medium trust solution until this feature gets implemented:
Create a Word document, which can process the HTML, and convert to PDF from Word.
This will work as long as your HTML is simple enough to be understood by Word. I'm using it for letters - which includes text formatting, some tables and margin/padding and it works well.
It won't producr a perfect image (like the full trust version), but...
Hope that helps.