Other than the already mentioned Java Junkies I don't know of any that even come close. I do, however, have a few theories as to why similar sites don't exist for other languages...
- Perl can be a very compact language. It doesn't take that many keystrokes to get your work done. This is great for discussion sites. In most cases you can easily reduce your problem to a few lines. You can also post complete applications that are well under 1000 lines. Which brings us to our next point...
- Perl is Open Source. Perl programmers tend to follow this example and share their code (for very good reasons that I won't get into here, see The Cathedral and the Bazaar). This also leads to a very helpful environment where others will not hesitate to provide you with good advice.
- Perl has a strange little culture of its own. Perl Poetry, Obfuscation, who comes up with this stuff? You don't see Java Poetry do you now? I'm still debating whether or not this is a good thing or not, but it is obvious there are some positive aspects to it.
- CPAN, CPAN, CPAN. Duplication of effort is BAD. If all Open Source programs had to write their own HTML Parsers much less would be accomplished. So you need to figure out what existing code to use. Reviewing every piece of code out there wouldn't be feasible, so what do you do? Ask your fellow programmers for recommendations of course.
- There's also the everything engine that the site runs on, and of course vroom and everyone who contributes to the site.
Those are just off the top of my head, the list could go on for pages. There are a few other languages that could fit with at least a couple of these points. In time I'm sure a Python Monks and a Ruby Monks will pop up, but I doubt they'll become as successful as this (rapidly growing) website.