90% of every Perl application you, personally, will ever really want to write is either already on CPAN or will be in the next year.
This is true, but only because I rarely find myself writing Perl applications because I really want to write them. Were it not for that caveat, that hasn't been true in any of my years of writing Perl, and I doubt that it will be true this year, either.
Perhaps I am just unlucky, or don't know where to look on CPAN for what I need, but I doubt that's it. Instead I think that it is because I wind up writing a lot of programs that are very specific to my local environment, and are solving problems that nobody else is interested in. Which is why I get paid, because I am doing stuff that I wouldn't do if I wasn't getting paid, and nobody else would do either.
For instance no matter how long I wait, I doubt that anyone will put on CPAN any of the reports that I need to write next week, all of which are very company specific.
Also I would like to point out that the 10 to 1 productivity differences with Perl are relative to very low-level languages, like C. Even a language like Java closes a significant fraction of that gap. Plus I don't believe that Perl is significantly more productive than, say, Python or Ruby. (In fact I believe that Ruby is actually more productive than Perl!) However I'll also admit that it is hard to find many real-world examples of really long programs written in highly productive languages.