This is good news. Several years late, and quite possibly too late, but good news nonetheless.
To be perfectly clear here, the guys at Tor per se (likely including Doherty) actually got this a long time ago. They’re science fiction guys, after all.
I remember them running a pilot project very similar to Baen’s ebook model several years back (they may even have been running it on Baen’s infrastructure), until it got tromped on by someone higher up the corporate food chain (Tor is owned by Macmillan, which in turn is owned by Holtzbrinck).
I’m very likely preaching to the choir here, but DRM does nothing to prevent piracy. Zero. Zip. Nada. It is completely and utterly ineffective, and always will be. The only thing it does is inconvenience your paying customers.
Corporate types always seem to think there’s going to be some magic bullet that will prevent digital files from being copied, but as Bruce Schneier once put it, trying to make digital files uncopyable is like trying to make water not wet.
As far as I know, every widely-deployed DRM scheme for ebooks has been cracked (no, I’m not linking to any of them, and no, I won’t tell you how to do it). New schemes are typically cracked within days. Remember, the pirate only has to crack the protection scheme once to produce a file that’s completely restriction-free.