Ok, first off - if you forget your root password, how would you go about resolving the problem? First of all, how do you enter single-user mode in arch using a boot cd, and secondly, how do you erase the root password in /etc/passwd (since the field is already empty...).
Secondly, how do you go about adding another superuser to the system? I assume it just involves adding the new user to wheel, and setting a UID of < 500?
I think password recovery is in the wiki, if its not it should be. Boot a live CD, chroot into the original system, run passwd, done.
I don't think the wheel method works, we don't set group permissions to wheel for most Arch stuff. Its much smarter to do this sort of thing using sudo.
The default /etc/sudoers contains a line that gives the members of the wheel group access to all commands, all you need to do is to uncomment that line and add the user to wheel.