I personally never download video games without paying (my brother is a video game developer; it would make family occasions uncomfortable), but going after file-sharers seems like a monumentally bad move for the video game industry. The ill-will generated by the RIAA's crusade against music sharers is not something the games industry needs. The industry already has a lot of enemies -- advocacy groups that want to censor content, politicians who want to appear pro-family by opposing violent video games, and the like. Suing consumers will certainly not help the industry's image, and should increase its enemy list.
EA Sports honcho Peter Moore argued as much at the Leipzig Games Convention: ""I'm not a huge fan of trying to punish your consumer," he said. "Albeit these people have clearly stolen intellectual property, I think there are better ways of resolving this within our power as developers and publishers."
Moore said that rather than letting the lawyers off their leashes, companies should be looking for other ways to play defense -- presumably better DRM or incentives for buying the game legit, like free updates or online play. Conveniences like digital distribution also help.
A shining example of a game that's avoided the pitfalls of piracy without resorting to the restrictions of DRM is an indie title, "Sins of Solar Empire." The game was developed by a previously unknown publishing house and distributed without any manner of copy protection whatsoever, but still managed to become a top-selling PC game during its run -- in part because free content updates were available only to those with a legit CD key. Maybe Atari and Codemasters would be rewarded if they followed suit?