Perl 5 will continue to exist and be maintained. Perl 5.7 is under active development now, 5.8 is ahead of us, and there may be more 5.X versions beyond that. ActiveState have committed to supporting Perl 5 after Perl 6 is released, and a few individual developers have said they will continue to work on Perl 5 for as long as necessary.
It will be at least 2 years until a stable Perl 6, and even longer until it's widespread. For comparison, consider that there are still people using Perl 4 more than five years after the release of the much more featureful Perl 5. Of course, popular uptake of Perl 6 depends on it being as much of an improvement over Perl 5 as Perl 5 was over Perl 4.
Nevertheless, this is not worrying us. We hope to do it right, rather than fast.