Yes, it is only a trial, and not for public consumption. And no, it is not a typo. perl5.004 is still being maintained, though perl5.005_03 is the most recent release. Get it, test it, and report back to p5p if you are so inclined.
This is Chip Salzenberg's first release of perl since the original perl5.004 and is available from his CPAN directory. Chip estimates that if all goes well, it could be ready for release in a week or two. But should anything not go well, you didn't hear that from us.