Honestly, I am not a fan of DRM, but in new releases (GOG excluded, of course) it really does seem to help, at least initially. From what I've seen, preventing piracy the first week, even only the first day, convinces impatient people to buy the game instead of pirating it.
I noticed this in particular with the release of Dark Athena, which, as some of you may know, had incredibly intrusive DRM. IIRC, its DRM was not cracked until about a week after its release, which caused many people to comment that they had purchased it in store instead of waiting for a cracked version.
Now, if you look at some games released completely without DRM, Demigod and World of Goo, you'll see that a lack of DRM (despite what many people who pirate say) often leads to increased piracy rates. I'm sure most of you are familiar with what happened with Demigod, which had
about 85% of day one users being pirates, which, in turn, lowered reviewers scores of the game (as it caused connection problems). World of Goo, according to one of the developers,
had a 90% piracy rate. Of course, there are other factors that contribute to the piracy amounts and, of course, I'm missing some arguments from some sides as well as relying on anecdotal evidence, but from what I've seen, DRM appears to help prevent piracy, despite what many pirates say (that they only pirate games with DRM).
This makes me view GOG, 2DBoy, Stardock, and other DRM-free groups as saints and companies who use DRM as normal, not as something malicious. It is pirates that garner scorn from me. After all, pirates are the primary reason for DRM.
Of course, there are lines that should not be crossed, and requiring full time internet connections for single-player play is, in my eyes, completely unacceptable (I'm looking at you, Command & Conquer 4). It's a shame, because I enjoyed Command & Conquer 3, despite what people said, and was looking forward to C&C 4 before I heard the news.