I don;t think they'll do nothing otherwise they would have confirmed that status quo remains and all used game controls / blocking rests with devs/publishers. But I think it would be a mistake to kill used (shared / swapped) games dead.

well gamestop tweeting praising the system could be a huge hint I think

Means..."we'll let our competition make the first move"

I'm thinking that it will be up to publishers and that we'll see some kind of registration system as with PC.

I feel like it's a ploy to get MS to go no-used games, or possibly both companies using it as leverage against gamestop margins.
I don't see either one having the block.

gamestop will most likely repay sony back with exclusive advertising, which is good :D

They might want MS to show their cards first before they spill the rest of the beans.

Either they haven't decided, or they're waiting for more info from SM or retailers.

Most likely, they'll make it easy for publishers to block used, that way, some publishers will do it, and Sony can shift the blame on to them, then if people get used to the idea Sony can roll it out for 1st party, and if people don't get used to it they won't.

Sony themselves said no game blocking and after Gamestop came out of Playstation destination with nothing but praise for the new console its a safe bet to say used games are a go on the PS4.

Just got back from Destination Playstation... #PS4 is clearly focused on developers & gamers. We have a lot of excitement ahead of us! ^CEO

— GameStop (@gamestop) February 27, 2013

The first vote option is nullified by the fact that some games you have to pay to access online. Uplay for Assassin's Creed (the few more recent titles) come to mind. Sony patented it, they'll do something. Something small like not allowing online play but something.