If you read some of the detail on that merger, the reason they are considering the deal is because the US is the most profitable and largest market for smartphones right now.
from the article you referenced. Son said the investment made sense because the U.S. is the world's biggest market in smartphones, and it was still growing.
And back to what I've been saying all along. Calypso having the US market is the best option, we don't need ROW. Still waiting on the final Markman docs. This friday another filing due in court case. What we need is a validation of infringement by Tmob from the federal court, then the receiver can call the other big boys and ask about licensing. They would be idiots to not license at that point.