As far as I can tell, some status icon descriptions may have been updated. In addition, the menu icons for some spells and abilities may also have been changed. Note all dats are untested. Let me know if there are problems.
You can download the DATs from filefront.com, or savefile.com.
To install the files, make sure you are fully logged out of FFXI and PlayOnline, then simply unzip the zip file to your PlayOnline\SquareEnix\Final Fantasy XI directory. Read the included readme file for instructions on how to install any of the new window tiles.
Note that this time I have included versions of the icon dat file that use SE's utsusemi icon and the different utsusemi icon. The default status icon dat file uses a different icon for the copy image status effect. If you prefer to use SE's icon, rename ROM\119\57-SE-utsusemi.DAT to ROM\119\57.DAT for the NA client, ROM\0\12-SE-utsusemi.DAT to ROM\0\12.DAT for the JP client, ROM\176\107-SE-utsusemi.DAT to ROM\176\107.DAT for the German client, or ROM\178\46-SE-utsusemi.DAT to ROM\178\46.DAT for the French client.
If you use the JP or EU client and prefer English language descriptions for the status icons then copy ROM\119\57.DAT to ROM\0\12.DAT for the JP client, ROM\119\57.DAT to ROM\176\107.DAT for the German client, or ROM\119\57.DAT to ROM\178\46.DAT for the French client.
DO NOT INSTALL WHILE LOGGED INTO FFXI or POL or the game may crash or behave strangely.
If you want to see what the UI looks like, see this older lj entry for a screenshot: FFXI UI 0.10 (September 23, 2006)
I also updated my zip file containing the original versions of these dats from the August 27th patch. If you accidentally delete the original dat files and you want to have them back, you can get them from Filefront here: ffxi-ui-original-aug27-2007.zip.