I don't consider myself in the position to ask for such changes but seeing Mark Shuttleworth talking about how he'd like having Gnome based on QT and the uncertainty in the gnome camp about the future of gtk 3.0 I was starting to ask myself if it was possible to have a Gnome-ish KDE.
As a warning I'm an extreme advocate of the hole Gnome KISS philosophy so some of my mock ups could be a bit too simplistic for you KDE guys. I'm just modifying existing applications based on some design philosophies from the gnome camp.
There are going to be several articles that will (hopefully) cover all of the (my) important applications.
Kate
What's with this session chooser thing.

Do i really need to select a session ?
I mean how often do you really need different sessions for an application
Wouldn't it be better to be a window after the Kate window is shown ? Or not to be displayed at all ?

Tip of the day is pretty decent and i don't have any cons about it. It can be disabled and it may show you some interesting options
from a beginner standpoint
Not from my standpoint it starts to get a bit messy.

Why do i need the Find in files and terminal buttons on the bottom of the screen ?
Also why is that filter system needed. Wouldn't it be better to have
something like Gedit "filter" system but improved. ?
Look at the screen shot for a better illustration of what i mean
and maybe it can do the real filtering as in Kate.

Also wouldn't it be better that the hole file system browser / documents sidebar to be more like the one from dolphin ? It's very configurable you can have
the views one under another or with tabs ( this could solve the problem of Kate
of not having a tab system and you constantly have to switch between the file browser and the documents).
Also wouldn't it be better that the file system browser would be the one used by the folder sidebar from Dolphin ? It's very slick and it's exactly what you need in an editor IMHO
a tree view of the file system.
Also the drop down from the top of the file system browser: wouldn't it be better to be similar to the one from dolphin such as in displays the current folder and when you click it it shows the sub folders and if you want to you can switch it to text mode and
enter your own.
Also just a small "hiccup" but i think that the top menu should be something like
File Edit View (so it's like all the other programs). The bookmark one should be made a side widget
The document one i think should be more like the one from gnome or it should dissapear completely. It doesn't provide a lot of functionality (as i said it would be nice if it would have the save-all / close all options.
Also the Back Forward is a bit strange. I wouldn't think from the start
that it actually goes trough the different opened documents.
Maybe this is because of the lack of tabs from Kate.
Also the window and the view menus should be merged together and some of their options should be moved into the settings manager. (after thinking about it for a while i think that it's prefectly fine to leave them as they are now).
Also please compare the following settings manager

The dolphin's one is on the left and Kate's is on the right.
As you can see it's an huge blank area on Kate's settings manager
The one from dolphin is better organized
Also all the subcategories from a specific topic are arranged in their own tab. Kate could use a better organization.
And now for the real torture. You're going to see my mock-up for a newer Kate editor. It is using elements from dolphin because I'm a really really bad graphic designer :D.

As you can see a bunch of my complaints are "fixed" very nicely in Dolphin.
In the next few days I'll add another mock-up with the settings manager.
/le
Damn i just saw that Dolphin has some nice tabs. I think the habit of trying to ctrl-shift-t for a new tab prevented me from seeing this earlier. Please use your imagination and replace my stupid little close tab icons with the ones from dolphin :P.
/le x2
I'm now on kde and hoping for a new driver from nvidia. X_x
Update: Read the comments below please for additional explanations