Yes, I've done lots of project using Perl.
If you try to write backup or simple script in Perl you are NOT going to like it as those tasks are pretty easy in KSH or Bash.
Just 2 week ago I finished LDAP directory server automation and integration with Postfix, Apache and other services. Here is something simple I'm working on right now, there is a text file which is updated everyday as follows (new domains added, updated or deleted) of like 30 web servers from command server:
My perl programs reads above file and make changes to TargetHost (another server in same IDC) and deploys required services. For example, if php is enabled a week ago and they disabled it in text file. My perl program will make changes to those server immediately and disable php access for that domain.
The next task is to put all those text config into pgsql and take action directly from browser instead of command line. So I'm deploying client server model (bot based) that take commands from central bot server and make changes to target UNIX box. All target box runs Debian. This may sound pretty complicated but with correct CPAN modules and good understanding of UNIX server programs one can deploy such solution in 4-6 weeks time including basic documentation.
The real question is does your job asks for complex automation? If so than only you are going to use Perl / Python or Ruby. There is also a book called Perl for sys admin. It is a good starting point.