While I DO realize that Perl is not the right tool for everything, I DO think it can be used for anything. In particular Object persistence can be as simple as SPOPS -- Simple Perl Object Persistence with Security
In short, you can do more with less code. Some of the 'stiffer' languages simple cannot express conveniently the same ideas as the flexible langugages like perl. The downside (in the case of perl 5 it is obvious) is the rather contorted design. Each chapter of Programming Perl basically has to mention one or more arcane exceptions to the rule, to make the language just a little bit more malleable.
This detracts from the language from a maintenance point of view, since the behaviour of program text becomes extremely dependent on the local situation it is presented in.
The great thing about Perl 6 from this point of view is that Larry Wall is trying to find an overall behavioural chararteristic of the language with fewer exceptions. This new look of the language even manages to add even more abilities within the same better managed functionality.
In particular OO will look better as will a lot of the rather happenstance functional programming features in P5
The danger in the rewrite is that the unfashionable (but to my mind - and every other perl mind around -very practical) idea that program code is often more readable when brief, will be abandoned in favor of the cleaner behaviour.
The common practice seems to be that the benefits of explicit design outweigh the disadvantages implied by this - namely verbose code. J2EE is an extreme case of this principle. All the thoughts are explicitly there at every moment. Personally I think it hurts.