I think the standard answer is that you can continue coding "perl 5" once perl 6 comes out, if you're so inclined. Perl 6 is intended to run perl 5 modules without modification (the keyword "package" indicates the following is perl 5 code, but a file that leads with the new keyword "class" will be interpreted as perl 6 code).

You might want to take a look at the Scott Walker book: Perl 6 Now, which is out from Apress. Essentially this is a book about how to write code immediately in a "perl6ish" style, using the various (varyingly scary) "Perl6" modules out on CPAN. I'm in the middle of reading it right now myself, and I think it's pretty good: lots of vary clear code examples, some fun example projects (e.g. hacking MOD files, the MIDI-plus-samples audio format that was popularized by the Amiga), and so on. Early on there's a lot of comparison of the way you can do things in perl 5 and the way you're expected to do things in perl 6, with some short, well-annotated code examples.

The only downside is that this is clearly a very quickly put together work, and the clarity of the writing itself doesn't always live up to the high standards of the perl books we're used to.