Functionality is not being moved out of the kernel and into userspace. It's being moved out of legacy freedesktop.org components (hald, ConsoleKit, PolicyKit, etc.) and into PID 1. Where should it be moved to? /dev/null.
I think you need to look a bit more closely at what's actually going into PID 1. See for example: http://people.debian.org/~stapelberg/docs/systemd-dependenci...
I don't see any logind/hostnamed/journald or any of that stuff in PID1.
hald has been dead forever.
PolicyKit is not being moved into systemd, nor is it getting systemd integration?
How do you want to replace ConsoleKit/logind? What should handle session management?
Something other than your init system. Not even Apple's launchd has the kinds of idiotic layering violations that systemd is full of.
Well, you'll be happy to learn that logind is a separate process entirely.
So moving functionality out of kernel mode and into user mode is great. The only steps after that are moving as much functionality as possible to the user, and then to nobody. We do trend towards minimum permissions for the sake of security for a reason.