done: reportbug (shot down hard). 

blender <-- nowhere to supply feature requests
dbus
linux dc++
driconf <-- hosted on freedesktop, but 
eclipse <-- probably tricky.
elinks <-- very unlikely
fluxbox <-- ?
gbdfed <-- maybe
gEDA <-- not likely (to old == they hate new things)
gftp <-- quite probable
gimp <-- planned
git  <-- not likely
gnome <-- Yes? no? Most likely no reason to tell them though
gnupg <--
gnuplot <--
gstreamer
gtk <-- already using it.. a bit?
gv
inkscape <-- reported
jscalibrator
mame
mplayer <-- (smplayer and other are using it) dunno
mediatomb <-- possible
mednafen <-- possible (might be reluctant, slow activity)
mozilla / firefox <-- worth a try? NEEDS IT
mupen64plus <--
neverball
pidgin / purple <-- not gonna happen
qt
screen
scummvm
ssh
songbird
svn
vim <-- lol! not going to happen
xvncviewer
wine
wmii
xbindkeys
xmess
xmoto <-- 
zsnes <-- not gonna happen

This is what i sent:

Bried description:
Should follow the XDG Base Directory Specification

Long description
For config files, temporary files and more the specification found at
http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
should be used.
Following such a standard gives several advantages, such as:
* Less cluttered home directories.
* Configurable path to config files.
* Backup/synchronization procedures become alot easier (copying multiple configurations easily and without getting temporary data, logs and such).
* Easier to maintain permissions for configuration files with sensitive data (only a single folder to protect).
and for many applications:
* Standard path for local cache data, logs and more, which are currently handled in various ways, often merged with config data or in some arbitrary file/folder.

The consistency of the system would increase if additional programs adhere to this standard as several apps already implement it.