Peter, could you pick the most appropriate group on http://groups.drupal.org and then work with the g.d.o folks to get a chipin fundraiser started to build the dreamweaver extension.  

How about $3K for starters, and see how many folks chipin?

In the last Drupal user experience survey of 2000 administrators, theming was consistently the number one issue of most important, hardest to do for most Drupal admins.  It's my understanding a weak implementation of Dreamweaver extensions for Mambo brought a lot of designers to Mambo simply because they could recognize the tools they needed.  

Also, any necessary changes to Drupal 6 that would need to be made to support the extension could still fall under the code freeze if you started now.

Cheers,
Kieran