Ubuntu to switch to Systemd on Monday

Systemd started as a replacement for initd, the initialisation daemon that is responsible for startup (if you run ps -A | head -n 2 you'll find init has the PID 1 because it's the first process to run on your computer, followed by the rest of the services), with the idea of making things more manageable.

In order to make things more sane they integrated other services natively like networking, process management, and mounting.

The big argument for Systemd is that it makes things much more sane, the current initd system is old and was mostly hacked together, so an effort to replace it is a good thing.

The big arguments against it is are you're replacing lots of small parts that work with a single massive part which is against the standard unix philosophy (do one thing and do it well (of course the kernel has always been exempt from this)), or that such a large amount of changes is introducing bugs (to which they often cite the large number of systems broken by Pulse when it first hit user land) and creating un required differences between Linux distros (not to mention Linux to BSD variants) which will cause more work for sysadmins and developers who will need to integrate with this content.