AJAX content management toolbox - is it possible or too revolutionary?

Hi,

I've been browsing recently for an AJAX CMS and couldn't find any. To clear up, what I mean by 'AJAX CMS' is NOT the 'end user experience', but rather the way page and templates are created.

For example, to create a new menu/block in administrative panel, one should go on a separate 'add menu' page and from the drop-down select the item's 'parent' as well as new menu item relative position. The same goes for new blocks, etc. Template and layout creation is mostly manual right now (from my understanding).

Isn't it possible to AJAX-inate the content management part of the CMS? So, instead of going to a separate page to add a menu, one could have just login as 'content editor', point a mouse to the appropriate place on the page he wants to add new menu item to, click, and from the context menu choose various content editing options. The same can go for layout and new blocks placement (click on an empty space on the sidebar and choose from the list of available blocks in the context menu. Once added, click on the block itself to edit its properties). Layout can be handled in a similar fashion (page is a set of split panels, drag the divider to change side, context menu gives an option to add new divider, etc). The main idea is to have a fully editable-in-place website, as an end-user sees it.

From my experience this usability features can easily boost system adoption... I don't know much of Drupal internals (consider me 'drupal novice'), but from my understanding the task is doable and is mostly about representing existing functionality in a different way (instead of directing user to a separate 'content editing' page, the functionality provided on that page is to be shown in the context AJAX components).

What do you think? Has this ever been considered?

Vlad

PS: the best example of bleeding edge AJAX I saw so far is 'Echo2': http://demo.nextapp.com/Demo/app. GWT might also be OK for the purpose...., though it's Java oriented.