If anybody is interested I've manage to integrate some drop-down & fly-out css only menu's into the SS/CMS framework (well via an included .ss file & some css).
Working examples can be found at www.dabnis-webdesign.com this is my testing site and the first menu is on the landing page.
I have attached the .ss file & the css file.
In essence all you need to do is replace the <% include Navigation %> line in the standard 'BlackCandy' theme page.ss file with <% include H_Navigation %>. make sure that you save the attached file in your templates/includes/ folder and the attached css file in the theme/them-name/css/ folder.
The last thing to do is to include the following in your page.php file.
Where you have Requirements::themedCSS("layout"); etc
Steve - the SS files attached to the first post. You can right click save or just copy and paste into a file in your project as an include so save it as for example DropDownMenu.ss in yourtheme/templates/includes/ and then in your theme you just need to include DropDownMenu - <% include DropDownMenu %>