I know a lot of people who bought the Nintendo DS and Wii, as well as X360 because they could pirate games.
The same thing applies to games than it does to movies. It's not because people can't share/pirate a game anymore they will buy it, on the contrary, they might not show any interest in it instead and not speak about it to friends who are actually buying their games.
If PS3 was hacked, there would easily be 50% more sold consoles.
The vast majority of games coming out on DS, Wii and X360 are not worth the money they are asking for it, so in a way people are just recovering money any way they can.
Besides, most of time too, a big franchise like Zelda, Mario or GTA, people actually still buy them because they want the real deal on their shelf.
If your game package is that good people want the real deal instead of the pirated version, then you deserve that money. Make it worth it to pay for your product, give something a pirated version will never have.