We've been asked, in person, in comment and email, and by Little Bun, who swears he has an Ethiopian brother out there:
We switched because that's where LittleOne is. We were waiting for a referral for Ethiopia, with openness to a range of medical and developmental issues as well as social and background issues (as before), and in the meantime, we were checking our agency's Waiting International Child list. There was LittleOne, whose needs matched our family's capabilities and preparation and special needs homestudy approval. We were aware that we would not be approved for their regular adoption process, but could be approved for a waiting child.
And so it is that we are on this new adventure. We've already begun exploring how to become a tri-cultural family -- fortunately, we have many friends and colleagues who share her birth culture and even region and we're looking forward to the challenge.