You'll probably have to backport to Intrepid, too, since the cutoff for adding new packages from Debian was back in June. The deadline for new packages for as-yet-unnamed 9.04 will probably be December or January.
Ubuntu manages getting out regular releases by adhering to a fixed time-schedule.
Importing from Debian Lenny to Ubuntu Intrepid will be easier, since both have Perl 5.10 and most Perl packages in Intrepid come from Lenny or Sid anyway ;)