There are a few feats scattered around that are limited by region of origin, I'm pretty sure, but in the main I think the answer to the question is (1) there's enough flavor already suggested in Eberron, and (2) regional feats take up a lot of space for being of such limited utility. (By which I mean any other feat, you might consider it at first, third, sixth level, and so on, or even more often if you get bonus feats, but regional feats can only be considered and chosen at one point in a PC's career.)
I'm personally not a big fan of regional feats to the extent that they're more powerful than average feats. I'm all in favor of suggested of feats by region (and Eberron does this), and I don't think encouraging choosing "appropriate" feats is a good reason to deliberately make a more powerful feat.