The alternative is 'throw out not completely useless stuff because I can't be arsed to sell it'. It's win win the way I see it, I'd dump half a truck of stuff on their dock if they'd offer this in Europe.
Almost the same here, except I keep it in a box in the shed. For example I have a Nexus 10 that I never use and I can't be arsed selling it but would happily sell it through eBay valet.
Are there not currently businesses that do exactly this? You drop things off and they list them. I ran one for a while (albeit in the states).
This was exactly what I was thinking too. In a weird way, eBay is competing with itself. There have always been companies where you can drop/ship your stuff off at and have them list it for you.