As described in the following topics root login via SSH is due to a changed OpenSSH configuration not possible anymore.
http://archlinuxarm.org/forum/viewtopic.php?f=3&t=9163
http://archlinuxarm.org/forum/viewtopic.php?f=57&t=9158
To enable root login via SSH /etc/ssh/sshd_config has to be adjusted.
In the installation instructions for Raspberry Pi http://archlinuxarm.org/platforms/armv6/raspberry-pi this possible problem is not yet described. I spent some time trying to login as root until I found the cause. (I am a relatively new archlinux user.)
I would suggest to update the installation instructions to point that problem out. Is that possible?
I assume that this also applies to the instructions for Raspberry Pi 2.
What are possible workarounds, especially in the case of the initial setup of the system?
I plugged the SD-Card in my Desktop and edited /etc/ssh/sshd_config.
Thanks a lot.
rpifan42