Great ideas. My personal pref would be a visual Wordpress site designer . I have tinkered with Joomla! and I'm not a big fan, but sure - if Coffeecup could come up with a visual designer that could export to Wordpress, Joomla!, and Drupal, that would be amazing.

For Wordpress, you'd need options that would allow you to create different page types so that you can create CMS sites and not just "bloggy" looking ones. But yeah - since Wordpress lets you do pretty much anything you'd need to do for a data-driven site, something that offers full WYSIWYG control over page templates would be incredibly useful.

There are two programs for Wordpress that offer hope but still fall short. Artisteer is a template-creator that shows you different designs until you find one you can live with. You then export the template and modify it manually.

Then there's ThemeDreamer, which offers WYSIWYG control for Wordpress but requires you to have Dreamweaver (which I don't). No one's got a standalone WYSIWYG editor for Wordpress or Joomla! yet, so here's a chance to be the first. The popular response could be enormous, as there's a huge demand.

Like these ideas. Personally, I'm with Michael above, I'd be all over a Wordpress site designer in a New York minute, it is so desperately needed. Would save those who know how to code a lot of time and enable novices to bang out WP themes.

Just getting to grips with Joomla! - so that would probably be cool too, but my #1 preference would be for a WP Designer/Editor, from Coffee Cup in 2010!

I use Artisteer, but it is quite limiting and I know CC could come up with something much better, catering to those who wanted to start from a blank template, or use existing templates(which would come with the software), as well as import and edit/tweak WP themes(or at least the CSS files). If you really wanted to go crazy, the ability to import a theme in zip format, as well, and then edit it, would be unbelievable! But I would settle for just being able to create themes and edit CSS files.

This all sounds interesting and it also could be a developer's nightmare
It's one thing having a CC visual php designer and another to service other CMS's.
When you say Joomla, Wordpress and Drupal in one sentence,, wow, they are all very different and with each of those also come constant updates(changes)..
I am not saying that it can't be done, but it's a big reach.