Would anyone like to see a movie and television based download service sort of like GOG?
There are loads of programmes out there which you either just can't get, are only sold in other regions or are being sold at exorbitant prices because someone hoarded the item before production was ended
The first two that come to my mind are:
Space above and beyond - only region 1
mortal combat conquest - can only find a dvd providing a handful of episodes
Does anyone else think that this could be a good idea or can you think of any large flaws with it?

I'd love to see something like it but I have a feeling that there'd be a hell of a lot of problems with it. Music licencing has screwed up several episodes of Dr Who coming out on DVD, 2 of them had to have the original music changed to something generic and The Chase has taken an age to come out because of 10 seconds of beatles footage from top of the pops. Its fair enough though, we all know that people would be only buying the DVDs for that 10 seconds of a beatles or hendrix song in the background so the publishers are right to demand full licencing fees...
SAAB was freaking awesome though, one of the best military shows of the era.

Music is a mess - you wonder if the companies/people actually want to sell products and understand the principle of free publicity.

There is Voddler. It's a web based commercial driven "Free" movie database with some rental movies too.
Voddler have both a web based and download client.

It's a shame Voddler isn't currently available outside of Sweden.

Well, it is but just in few Countries, I'm not sure which thou. But as i have heard they are constantly expanding. The legal thingies are what's holding them back from spreading like a pestilence across the international web.

Well, I've got BT Vision which is film/tv on demand.
I also use LoveFilm, which allows certain stuff to be watched online.
The problems are mostly with very new series (House, V, Lost, etc.) that aren't available unless you have Sky (satellite broadcaster), and very old stuff which has terrible rights problems (of the sort GOG has with certain games I've no doubt, where no one can trace the appropriate people to give the okay).
For example, I can watch on demand Doctor Who, but only the past three series (Ecclestone and Tennant), the current series has slightly limited availability (BBC iPlayer or I can watch it live or record it). Older series are currently unavailable except if you want to rent the DVDs (some available through lovefilm) or buy the DVDs (very expensive for stuff thats quite old now!).
Hulu is still a long way off for the UK, we were supposed to have it in Sept '09, and I've heard nothing since the last delay (literally nothing in the past few months, haven't seen any reporting about it or why it's delayed).
It also annoys me that I used to be able to watch the Daily Show/Colbert Report online, and since about summer '09 that's been blocked for the UK.
Basically, copyright and IP are getting in the way of content distribution in this country, and I don't see that getting any better any time soon.
Clearing that up would be a big boost to media companies, as I've no doubt it would help reduce piracy.

I've got the same set up as you, I wise Love Film to watch TV series that aren't on BT vision. One thing that's annoying about BT vision is that sometimes the series drops off the service before I can watch it all. They seam to be getting more old stuff now though as TJ Hooker and Charlies Angles have recently appeared.