Never happen, eh?  I sold a DSi with digital content. So, that taste in your mouth right now- that's called crow.  Because you ate it.  You ate crow.  Crow eater.

There would be no used games

I'm not sure what you are trying to say.

How do u have a used digital item?

It's already possible on Green Man Gaming. Other than that, don't really know any other places though... And I don't see it happening any time soon, either.

Reselling an item (your OP) is basically "used." In my post used = resell. When I said new, I meant "not resold."

I could see Steam trying some things... the resale value would probably be extremely low, but maybe change 10 old games for a new one?

I have a hard time explaining what I mean. But if u sell the digital game back to the network then they can just keep selling it as new since ur not opening a package or anything like that. Basically just a way to get people to commit to digital

It doesn't need to happen. Digital games just need to be priced lower, as they cost the publishers much less than retail.

However, if it were up to me, if I ran something like Live or PSN, I would give store credit back on purchases instead. Let's say something like 10%. Tie it in with your subscription service. Someone buys a $60 game, they get $6 back in store credit. That's both a reward and an incentive to buy new games. Amazon often does something similar and I think it works well for them. A $10 Amazon credit will often make me pull the trigger on a new game.

That way, you get to keep the game, things are a lot less complicated, and you'd even get a reward for games you wouldn't have sold in the first place.

It is hard to say one way or another. As a purchaser the idea of used digital software is really pointless. Steam, Sony, and Microsoft already put up 50 - 80 % off sales on many good games, or just plain give them away as part of a subscription. If you can pick up the best game from 2 years ago for $5 I don't see the reason for not buying new.

The same applies for movies, there was a time when VHS or DVDs sat and no one would watch them so people put them out in yard sales. Now the movie is in your library for all time. You keep it in the cloud and stream or D/L it at you leisure. It is not taking up space in the house, and people can already find movies on sale for as little as 2 or 3 dollars through digital, or for 9 dollars a month on a streaming service.

Additionally, I don't doubt the platform holder would take a cut on every used content sold since you are using there service to make the transaction. So I fell it will probably happen just for the fact that SCE, MS, ect. will want a cut of every pie they can get there hands on.