After what was probably too long trying to avoid it, I'm finally diving head-first into Perl. I feel learning Perl takes more investigative work than some languages, as what's best practice is somewhat subjective and has changed since a few of the more popular books have been published (e.g. Programming Perl). I've made a few observations:

• Ruby borrows Perl's syntax more than I realized (e.g., postfix conditionals)
• The breadth of libraries available is amazing -- by far the best of any language I've used -- and people really seem to be good about writing good docs for their code.
• cpanminus is by far the best way to use CPAN; it works exactly how I would expect a package management system would in 2010, unlike the bevy of features you need to configure when using the perl -MCPAN -eshell CLI.
• Moose seems like a very impressive library, and seems much more natural than manually blessing modules the "old-school" way.
• Variable Context-awareness is something that took me awhile to understand, but now it seems natural to me. I think dealing with references adds another layer of complexity that can be intimidating to new users having to deal with both at the same time.
• I'm not sure about how argument passing is implemented in Perl, but thinking of it as a simple stack makes the most sense to me.
• Implicit variable passing (@_ and $_) seem like a bad idea for maintainability, but really cut down on the tedium of dealing with variable names. I'm growing to like the feature.
• Perl's efforts to be backwards-compatible has left it with a lot of vestigial syntax; in a way it suffers from the same problems C++ does in trying to please too many. The solution for a lot of teams using C++ is to use a well-defined subset of the features, and I believe this parallels making sure to use the latest features of Perl as well.

All in all I'm liking it. Next up: Clojure?