I think that if we increased the types to the resolution of O'Caml or Haskell (or even C/Java), it wouldn't really be Perl anymore. For this reason, I don't really advocate that Perl's type system be modified too much beyond its current state.

What I do advocate is that type safety is a Good Thing(tm), doesn't get in your way when implemented well, and we need a language that can take the idea out of acadamia and into the real world (like what Java did for VMs).