Robert et al., write in favor of shooting HD and I'll concur. Here's my summary of reasons for my own preference to shooting HD, even when the "deliverable" is 320x240 iPod or web video.
1. Shooting in an HD format like HDV is more "future-proof" that SD DV. If you edit using a editor that allows you to re-capture media in a different format, then it's trivial to take a show you edited in SD and recapture the pieces you need to create an HD version, for example, using the Media Manager feature in Final Cut, other editors have similar features. 2. We're evolving towards HD in terms of display devices in the hands of consumers. HD looks much better on the rapidly growing number of 1080i and 1080p large screen televisions out there, as well as the ubiquitous large LCD displays on laptops. As prices continue to drop, this will become the new standard for home entertainment. Most laptops are HD capable (1024x768 screens seem to be the new minimum with most screens larger). 3. It's not really a burden to shoot HDV and you need not edit in HDV (which requires a faster machine that DV for editing due to use of MPEG-2 format). You can simply capture SD DV through the camera, edit SD DV and deal with the fast workflow of SD DV. If you need more resolution for a special presentation or whatever, see #1 above. 4. The new generation of little HDV camcorders are almost as small as their DV counterparts. And it's more versatile to have the option of shooting DV or HDV. 5. We're evolving towards HD in production tools. Even digital still cameras with movie modes are moving towards higher resolution. 640x480 VGA is a good baseline right now, and compatible with SD DV, but the resolution is creeping up. 6. We're evolving towards HD in terms of distribution infrastructure. Internet-based television will not only soon equal the quality of terrestrial broadcast and cable HDTV, it will exceed it once Fibre becomes more common. This may not be a concern, but producers are always thinking about future-proofing media that has a long shelf- life, see #1 above. 7. Creative and political expression and the exchange of knowledge and ideas is more important that anything in points #1 through #6 above. The message will always transcend the medium and therefore points #1 though #6 are minor compared to the importance of the expressive work itself, especially in the era of participatory media, we have the option to work with a wide range of tools. David.
