So now that I've got stacks of old DVD-R's lying around with old projects, I'd like to archive these movies to an external HDD.
I'd eventually like to be able to:
1. Re-burn the movie to a new DVD from the archived HDD
2. View the movie directly from the HDD and Windows Media Center, Nero, etc.

I use a Drobo (Data Robotics, Inc. (http://www.drobo.com)) for safe storage.
It is a smart raid systems which makes sure that if one of the two to four harddisks fails, the information is still on the other(s). It notifies any failures and you can upgrade easily to higher capacity. Redundant storage is the only fail safe system. The only thing it will not account for is when the unit gets distroyed by fire or other external cause.

With it's firewire connection you can even use it as your prime external harddisk (no backup procedure for future projects required).

So now that I've got stacks of old DVD-R's lying around with old projects, I'd like to archive these movies to an external HDD. snipped

I'm puzzled why anyone would want to move stuff from a reasonably permanent medium to one that is bound (by the laws of physics) to grind to a halt one day? If I had concerns I'd burn a second copy of the DVD and store it off site. Or maybe I've missed something?

I'm afraid you really are missing a lot, indeed, Philip! Theoretically writable DVDs are "permanent storage"... but only theoretically. I have several DVDs that show signs of sickness/death after just a few years. Pressed DVDs is another story, but those we burn on computer will fail after just a few years. Once a DVD failed, you can kiss it good bye, while in most cases a hard drive can be saved - better yet, use a RAID 1.

Vince, what is your question? I am doing the same with my stuff, copying everything to hard drives and playing from there with my WD HD media player.

I hope you're wrong Ervin if only because an awful lot of businesses and careers in wedding videos are going to be facing big problems in the nearish future if the products we make and sell are going to become unplayable.

As I said, I understood that the long term reliability of DVD's was considered very sound, (burned less so than pressed as you say) depending on the storage but then wedding videos tend to get put away in dark cupboards anyway. Your news isn't good.

I love your optimism; unfortunately it can't be backed by facts. The issues is very well documented, just look around on the internet.

Even disks specifically "designed" to last for 100 years, the gold archival variety, are marketed with precaution, and without too much certainty.

Perhaps this excerpt from a study summerizes it best: "Certified, archival-quality recordable optical media is unavailable and may never be available. While there is interest in long-lasting, "archival-quality" optical media in specific markets, no independent certification body exists. The costs of testing and certification, when compared to the potential market size and the rapid evolution in optical media, has deterred manufacturers from marketing certified, archival-grade optical media". [http://www.thexlab.com/faqs/opticalmedialongevity.html].

As sexy as a good looking DVD case and a shiny printed label on the disk might be, its days are numbered. So are hard drive's days, but keep in mind, hard drives have a disk in a sturdy metal enclosure in total dark, mostly airtight - compare that to a DVD that can be touched, scratched, exposed to light, etc.

You decide what's best for you. For me it's copying everything onto hard drives. Even price-wise it makes more sense as of 2009 - a 1TB hard drive can hold over 200 DVD-5s; high quality blank DVDs will cost you more than the drive.

I definitely wouldn't use DVD's as a backup medium, as they can easily scratch and will deteriorate over a short period of time (not all discs are the same, some will last over 10 years). Hard Drives are the way to go, especially a RAID array, which allows for failure of one or even multiple drives without losing any data.

We actually use 2 separate raid arrays, one on-site, and one off-site just in case of fire, theft, or some other disaster.

Just make sure you keep the image backed up on hard drives so if your clients come back to you because their disc stopped working, you can burn them another one.

Just to add to your #2 question, we do this all the time. We mount the backed up ISO images using DAEMON TOOLS. This causes your computer to think you just placed the disc in a drive, and it will launch whatever software dvd player you have installed (we use Power DVD Ultra, so we can mount Blu-ray images as well)

I see we are talking about DVD's here, how about Blu-rays? Their shelf life any better or about the same?