As Abigail-II noted Perl *is* able to handle 64-bit and has been for some time.
We run perl on a Dec/Compaq/HP Alpha processor, and that has been 64-bit for many years (10? 11? 13? I can't remember). I can't remember which Perl release gave 64 bit int's, but there was absolutely no significant change: we ran both Unix and VMS on Alphas, Solaris on sparc and ICL-DRS/NX on sparc, and Win32-something-or-other on i386 and happily used the same source on all platforms!
Side-note: Perl is *truely* portable

So the answers to your questions are something in the order of:

1. No, it is already
2. It has happened, by much hard work from several p5p-members
3. In no way at all