Comment 4 for bug 148985

a temporary workaround to get rid of the broken dependency is going to /var/cache/apt/archives and issuing command sudo dpkg -i gimp-python_2.4.0~rc3-1ubuntu4_i386.deb which will downgrade gimp-python to previous version (if available in cache).

This will prevent "broken packages" message to appear, as far as you do not update gimp and gimp-python packages again to this broken revision.