Other than the Feyspires, there really wasn't anything changed, and certainly nothing major. I mean, Tieflings have been in Ohr Kaluun as long as we've known what Ohr Kaluun was (so, since whenever SoS was released), and D-born's addition was in the most logical place they'd fit, and their very rare to boot. And the dmark change? Only in the rules. Flavor-wise, they were still race-restricted.
IOW, d. - "There's a difference?"
And I should know. Eberron is my thing.
EDIT: I'm not actually 100% sure on the Tiefling bit. They've certainly been in the setting from the start, though, and honestly, ancient magocracy that trafficked with fiends? Yeah, Tieflings fit there. The other place they're seen a lot is the Demon Wastes, and that's regardless of edition.