I tried the patch of Chris Heath on Fedora Core 2 and here is my take, from the user's point of view.
The patch works, surprisingly very well. It can be easily intergrated to the various distributions simply by modifying the /etc/sysconfig/i18n and /etc/sysconfig/keyboard configuration files.
The system scripts essentially call the following two commands (assuming we are already in Unicode mode):
% setfont <font-name> -m <console-screen-map>
% loadkeys <keymap>
For example, For Spanish:
% setfont latarcyrheb-sun16 -m 8859-1
% loadkeys es
For Finish:
% setfont latarcyrheb-sun16 -m 8859-1
% loadkeys fi
For Greek:
% setfont iso07u-16 -m 8859-7
% loadkeys gr
The character and key maps used are the "old" 8-bit versions. setfonts loads a Unicode map with the "-u" options instead of "-m". Also, the key maps for a few languages have been updates (for example, "gr-utf" for Greek). The new files (very few) cannot be used here. No need to update them ;-).
I tried a few languages and what follows shows characters produced from the console with composing. I used "vim" as my editor.
gr: Greek ά έ ί ό ύ ώ ϊ ϋ ϊ Ά Έ Ί Ή Ύ Ϋ
es: Spanish ñ á é í ý ú ü ï ÿ ä ë
nl: Dutch á é í ó ú ý à è ì ò ù
cz: Czech ä ë ö
us-ascentos: á é í ó ú ý ä ë ï ö ü ÿ
cf: french-canadian à è ì ò ù
fi: Finish ä ë ï ö ü â ê î ô û
fr French â ê î ô û ä ë ï ö ü ÿ
Therefore, from the user's point of view the patch works.