The gimp-2.0.desktop file (in /usr/share/applications for me) should be edited to reflect themable icons; currently it is hardcoded for the stock icon. A trivial matter; the line Icon={PREFIX}/gimp/2.0/images/wilber-icon.png should be changed to Icon=wilber-icon
I'm closing 9 bugs at once, since these bugs should be fixed in my 2.2.7 ebuild of the gimp. ( just committed to the unstable tree ) If you find that your bug was not fixed in the 2.2.7 ebuild, please open a new bug with what it is or is not still doing. Thanks for the attachments and comment, they helped!
This doesn't work (might be the default theme, but that is important). Maybe if we install the gimp icon in a more 'default' place, but that might become a problem with multiple slots.
fixed with symlink, bug upstream about moving the icon @ http://bugzilla.gnome.org/show_bug.cgi?id=307705 marking resolved.