Changing PACKAGE_CLASSES to "package_deb" and building core-image-minimal resulted in a failure in do_rootfs. Log attached - seems like the perl path may be incorrect.
Created attachment 284 [details] build log
http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=rpurdie/useradd2&id=7caecd0c35872f0dba2f818e26e0994d43a5e609 fixes the dpkg problem but it fails later in do_rootfs now :(
http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=87377c2b5788b86c6aecaf47f9cef511c23edc12 fixes the other issues seen and deb based images work again.