walikngthecow: this is a good question, that I (and many others) have been wrestling with, from time to time.

In my opinion, in comparison to Python, Perl is more expressive, more powerful, and much neater in its language architecture. I think the Perl sigil methodology is brilliant (namely, that scalars start with a '$', arrays with a '@', hashes with a '%' and so on); that the operator determines the expression context, instead of the variable type; these and several other pillars of the Perl language make it really distinct.

On the other hand, many areas of the Python language seem like a kludge (for example, its regex implementation, and its implementation of array slicing).

If you know Perl well - if you have mastered Perl - then you have in your possession a considerably more powerful tool than Python.

Some additional considerations:
1. On a sizable web project, you need to use a tool - I understand that "Catalyst" is a popular one - but I've never used it. I have been using wxPerl.
2. It seems to me that the user base of Python is much, much larger than that of Perl (maybe because of the rumors that Google is using Python internally?) and that the Perl user base is slowly shrinking. A couple of years ago, there was a resurgence in Perl, since the biology departments, in universities, have discovered that it's convenient (and powerful) to use Perl for manipulating genome sequences. But since then, it seems that Perl usage is flat and decreasing.

Helen