Bethesda Softworks has confirmed via Twitter that RAGE will get the full Steamworks treatment.
Since folks are asking... we can confirm that RAGE will use Steamworks on PC

In other RAGE news, Tim Willits has confirmed that the sewer levels of the upcoming post-apocalyptic shooter will only be accessible to those who buy the game new:

If you bought the game new, that would be open for you. You still have to download it, but you don't have to pay for it. Those hatches are all over. Most people never find them. But as soon as you do, you're like, oh. And then you start to look for it. That's our first-time buyer incentive.

But as you can tell, most people never even see it. I can tell you, some people will buy Rage, download that, and still never set foot in those things. They just won't. I think that's fair. It's cool. It's outside the main path. We're not detracting from anything. But I know some consumers, when you can't avoid it, then you get a little touchy subject.