Definitely!
I've looked at d20 Modern on several occasions...well, OK, about a thousand...and have resisted purchasing it, and will likely continue to do so. A full-on DarkMatter setting hardcover, however, would be another story.
I know that DarkMatter elements have crept in to several d20 Modern products, but it's not really been enough so far to entice me to purchase the product line. I was/am, however, a bit of a DarkMatter geek. DarkMatter was, in my opinion, the best setting book ever released for a modern-era RPG, and a DarkMatter hardcover for d20 Modern would most assuredly sell me on the line.
That said, I don't see it happening. WotC would be much more likely to release another product supporting Urban Arcana or a more in-depth look at one of the other mini-settings described in the d20 Modern book.
Regards,
Darrell King