As a sys and middleware admin I would advice learning java + a strong scripting language, for instance perl.
A sys admin, or a dba or a middleware admin can do all his/or her automated development-type works by using something these 2 -> perl + java.
It is also important to know these kinds of languages for dealing with the application issues. Sometimes you need to go and check the code.. This seems like a good skill set -> SQL(+SQL Tuning), PL/SQL, Java, Bash, Perl.. Aha, you may also add Python to the list :)