(Warframe) - Dragon & Typhoon-
(Neverwinter) - Trickster Rogue & Guardian Fighter -
lol Keep seeing this argument. You really think if Sony confirmed they were going ahead with this, Microsoft wouldn't follow suit with their own method of locking games to an account? It would become standard practice at that point so it wouldn't be a negative against the system, so the consoles would still be competing on the same grounds as they do now (features/exclusives/etc), but would be making a ton more money because of the death of the used market. There are no drawbacks to Microsoft in this scenario.
I know people are trying to make out that Microsoft could take some of the PS4's potential customers if they decided to not implement their own system, but I very much doubt it would be as profitable as you're thinking, and certainly not a guaranteed profit like in the above scenario. The only customers they would get would be the ones who buy so many used games that this is a big deal for them, which means Microsoft will get very little money from them, or in the worst case scenario actually lose money to some of them as they sell the console at a loss and never see any money from the games those customers buy used. You're also ignoring the fact that a lot of people will stick with the PS4 because of brand loyalty, (probably) free PSN, controller, features, exclusives, etc, no matter what.
So basically, Sony haven't shot themselves in the foot, they're just revving their engines in the game of chicken they're playing with Microsoft as to who officially announces their method for killing used game sales first.