I'm a sysadmin for several NT, Solaris, and Linux boxes.  I currently
use both Perl and increasingly Python to manage my systems.  I am
beginning to enjoy Ruby quite a bit but it seemingly is devoid of NT
related functionality in the areas of:

services management
printer and disk management
COM(+)
user and group administration
security
sockets
ODBC

Can anyone comment on any available modules (not in Beta, etc.) that
are available and mature in nature?

I believe that if there is anything that prevents the more widespread
use of Ruby on WIN32 is that it may be lacking these tools.