You can convert your Perl 5 scripts to bytecode, and any one can -MO=Deparse them back to something (reasonably) close to the original code.
In Perl 6 you will (I assume) be able to convert your scripts to byte code tartgeting Parrot, and some one will eventualy make a Deparser for Parrot/Perl 6. Perl 6 will probably not be that much friendlier to source hiding than Perl 5 is.
You could always try B::C if your willing to give up some portability.
Diotalevi explained to me that you can't convert Perl to real bytecode. There's some compiler that does a bad job, then there's the not-real bytecode that could be converted back without knowing machine language.
It really pisses me off that people are being misled into thinking Perl is as safe as any other language when it comes to concealing the source code. The inability to do that well also makes copy protection less safe.
Even, say, Java bytecode can be deparsed. OK, there are code obfuscators, which do various clever tricks (for example producing valid bytecode which works in the JVM but which could never be produced from valid Java code) and garbling variable/sub/class names to prevent them from being understood. You can easily obfuscate (Acme::Bleach anyone?) Perl code, and garble the names for good measure. I guess the fact that Perl 6 will compile to bytecode will make other forms of source protection easier to implement than for Perl 5 though.