Part of that problem is just the term "cyclocross". Disc brakes aren't allowed in all cyclocross competitions (not yet, anyway), and the cyclocross label is usually attached to bikes meant for racing. So, when you peruse a catalog, the 'cross bikes likely will have cantis.

That leaves the "commuter" and "road" categories. Commuter bikes, as far as catalogs are concerned, are stereotypically flat bar bikes, maybe lighter than a manufacturer's hybrids (if they're different at all). Road bikes are usually expected to be race-ready, and weight weenies don't like disc brakes.

So, after all of that, we're left with the understanding that a popular form of do-it-all bike is difficult to categorize. Drops like a road bike, mounting tabs like a commuter or tourer, fenders like a cruiser, discs like a mountain bike -- what section of a manufacturer's catalog would you put that into (hypothetically speaking, anyway)?

Because of this, we're left to fend for ourselves. Here's a thread collecting the known drop bar'd-disc braked bikes that are configured as such straight from the manufacturer.
http://www.bikeforums.net/showthread...0c-off-the-peg

Some are cyclocross, some are urban, some are road, some are commuter, some are tourers...