Bored by seeing galeon2's and gnome-terminal's tabs on top of the 
MDI window i decided to create a patch fixing this problem. The resulting 
code introduces a GConf key "/desktop/gnome/interface/mdi_tab_position", 
updates gnome-ui-properties, introduces gnome_add_setup_mdi_notebook in 
libgnomeui/gnome-app-helper.h.

Still questionary:

- should there really be the "preferred MDI style" entry in gnome-ui-properties -- it's easy to remove the code again
- is gnome-ui-properties the right capplet, should it get a notebook-interface, should the MDI stuff go into a separate capplet
                
Rationale

Guess it's perception thing (as for the buttons in dialogs): When
surfing with galeon I personally use the tabs to download pages in the
packground. When using the terminal I'm putting related background tasks 
into other tabs. Background is the keyword in both use cases: The 
existence of the tabs is an important convenience feature, keeps the 
desktop uncluttered... But the tasks running in them are background tasks, 
they are not important for my current workflow, placed at the top with all 
the important control elements (location field, back/forward/reload-
button) the tabs are disturbing, gaining far too much perception. So I 
like to have them at the bottom. The idea is: I only have one pair of 
eyes, one pair of hands so I only can use on tab at the moment. The other 
tabs are nice to exists and it's important that they are easy to access, 
_but_ they shall not disturb my perception. 

From my knowledge others  see it as more important to have 
of a window at one place. So for them the tabs definitly have to go to the 
top of a window. Since this (perception + workflow vs. 
everything-in-one-place) are to contrary but acceptable philosophies tab 
position should be configurable globally. Even with your important 
reduce-the-(user-visible)-options campain.


What about the posiblity to put the tabs to the left or the right. 
Not nearly as neccessary for me as the top vs. bottom choice even if I 
prefer to have editor tabs at the left - simply since I maximize editor 
windows vertically and having the editor tabs on the left saves space, is 
more readable. But well, since gedit doesn't have syntax+brace 
highlighting I'll stay with nedit and let my window manager place 
miniicons for each editor window at the left desktop border... ;-)