What kind of HDV? If it's 1080, you can import it through a Canon HDV camcorder like an HV20 and just tell it to force its firewire output to be DV, and it'll do the conversion for you on the fly.
You can do it either way. The in-camera way will result in much faster editing and mastering, but you'll be working with standard-def footage. If you need a high-def master, import it as HD and finish it as HD, and then render out a DV version.