IFrames have some advantages, but an update to the interface (with some good ajax/silverlight techniques) would be nice. It now has a bit dated style (I know, personal opinion), but it is not in style with the new types of interface. For example Office for the web or Axinom CMS (http://en.axcms.net/en_axcms_contentmanagement.AxCMS)

When an editor browses the site in CMS Desk the content tree on the left does not reflect the current location in the site. When the editor has reached the page he wants to edit and clicks the Form or Properties tab, he is not actually editing that page!

The messages and feedback that are displayed on the site to the user are very difficult to notice. They should be clearly visible (e.g. colored, noticeable location) and have an option to be closed.
For examples see: http://www.jankoatwarpspeed.com/post/2008/05/28/Create-MessageBox-user-control-using-ASPNET-and-CSS.aspx

I think the use of 3rd party controls would improve usability, reduce code-clutter and most importantly free up time for Kentico developers to focus on implementing great ideas instead of struggling with UI code.

To avoid the standard translation dialog from clicking the (*) pages in content tree, ther should be a possiblity to hidde the the (*) pages from the content tree by a special setting for a website and/or culture or as an additional user property under allowed languages

I would like to be able to deep link into any area of the administrative site, rather than being required to navigate to the location manually. If I wanted to directly edit a transformation in CMSSiteManager,
I should be able to navigate to http://website/cmssitemanager/documenttypes/documenttypename/Transformations/transformationname/edit as an example. This has two benefits:
1. It speed my time up as I develop
2. It add support for "back" functionality that allows me to traverse my history by creating a trail of "locations" that I have been to.

When switching back from preview to edit mode, system should recognize if the content of the document is edited in form mode (i.e. blog post) and switch user directly to a Form Tab instead of a Page Tab.

When there images uploaded as attachments to a document that were insert via the editable text region the image link breaks when you move the document somewhere else in the tree. This should be fixed.

The admin and editor interfaces of Kentico CMS would benefit greatly by taking inspiration from Squarespace. I'm not saying we need the point and click control over every design element in our websites, just the look 'n' feel and the smooth handling of the interface.

If an administrator has several places in the Site Manager that he visits often (like the event log, users, permissions) then he could have a personalized pop-up menu (maybe in the bottom right of the screen) that contains shortcuts to these places in the system.

In the UI personalization feature, you can allow or deny certain tabs and features within those tabs be accessible. The Content tab seems to be kind of wide open. I would like to see that if a user owns certain pages, only those pages show up for editing while in the Content tab. So Say a user has 3 pages that he/she owns, when they click on Content, only those 3 pages are visible for editing in the tree navigation on the left.

At any place in the CMSDesk and CMSSiteManager, please add the ability to test the correct loading of an assembly. For example, paymentgateway DLL, after you specifiy namespace /assembly information, you should be able to "test" that Kentico CMS can find it correctly, which would reduce frustration in ensuring proper configuration.

Allow Insert, Update and Delete on Multiple documents.

The Move dialog box should remember the last selected page from the previous Move operation, for cases where lots of moves need to happen on multiple files.

We suggested this for the Image selection dialog and it was added in Kentico 5.0. But this should really be a mechanic for all the Document selector dialogs, not just Image document selection.

When you have an installation with multiple sites that shares the same custom document type but different transformations, it is hard to keep track of what transformation belongs to which site.

It would be nice to restrict the usage of transformations by site and been able to browse all transformations or the ones that are allowed to some specific site