I've though about it and although I think that DPkg::Post-Install-Pkgs is a good idea the solution is not that simple as I suggested in the attached patch.
In the patch I suggested issuing commands specified with the option after successful execution of the loop passing names of the packages to dpkg. This is not correct. The best place to execute those commands is after successful execution of the dpkg on a particular package and pass on the standard input only the name of this package not the names of all packages. This way DPkg::Post-Install-Pkgs commands will be executed for all successfully installed packages and won't be invoked for failed ones. When I have time, I'll try to come up with the right delta. Thanks, Igor

