Perl, Python and Ruby are all excellent languages IMHO. All three have excellent testing tools and thriving QA communities. As a testing/QA professional, familiarity with all three couldn't do you any harm. In case it helps convince you that Perl is not dying, notice the top eleven languages from the latest Tiobe Index of Programming Languages:

Dec  Dec                            Delta
2011 2010  Language       Rating   Dec 2010  Status
 1    1    Java           17.561%   -0.44%     A
 2    2    C              17.057%   +0.98%     A
 3    3    C++             8.252%   -0.76%     A
 4    5    C#              8.205%   +1.52%     A
 5    8    Objective-C     6.805%   +3.56%     A
 6    4    PHP             6.001%   -1.51%     A
 7    7    (Visual) Basic  4.757%   -0.36%     A
 8    6    Python          3.492%   -2.99%     A
 9    9    Perl            2.472%   +0.14%     A
10   12    JavaScript      2.199%   +0.69%     A
11   11    Ruby            1.494%   -0.29%     A
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Perl increased (+0.14%) in the past year, while Python (-2.99%) and Ruby (-0.29%) both decreased. In any case, Tiobe rates all three as safe-to-adopt "A Grade" languages. I agree.

As for QA and Testing, Perl has excellent testing tools, a long tradition of testing (automated tests have been bundled with Perl since version 1.0 over twenty years ago) and a very talented and active QA community, notably the CPAN testers and qa.perl.org -- a lot of their current work is done on the perl-qa mailing list and at annual perl qa hackathons.