the publishers and developers claim that the industry is in trouble (ie: studios closing in numbers) because of poor sales.
reasons for the bad sales numbers are being blamed on piracy, used games sales not giving them cuts, and the cost to develop games being too high to make up for the margins they receive on game sales.
by putting in this used game DRM, they're getting a cut of all used sales. that helps them make up more of the cost of making games, and from what they "lose" from piracy. the DRM also helps prevent said piracy.
by that math, there's no way they're going to lower the price of retail games, because it puts them right back at square one where they aren't getting the cost of development covered as much as they want. putting even more importance on getting high sales numbers. EDIT: and by getting the cost covered, i mean making less in PROFIT than what it cost to make the game. they get the development cost paid for, but if they aren't making enough money to make another game, then it's considered bad... i guess.
with this DRM, buying a game brand new at retail is going to be extremely risky to the end user because if it turns out to be shit, it will be a complicated process trading back in (which lets be honest, is a deterrent from trading it in at all) and if they do, they won't get as much back for it if everyone else is getting a share too. with the used games priced so closely to the brand new counterparts users won't have much reason to buy used anyway if they can get a brand new disc/box etc. so used games is going to dry up too. the AAA games are going to keep selling just as well as they always do, but everything below that is going to suffer because there won't be as many impulse buys.
the way i see Sony fitting in with all this, just based on what's available on their platforms, they're heavy on the "everything below AAA" side of things, and it could be catastrophic for them to see software sales put on the brakes. that's where platform holders make money after all. that and services. MS isn't going to be in as much trouble from slowing sales of games at retail because they make money from a lot of different things. to me it really seems like they are simply trying to buy publisher support.