The Astros have added a 2nd Dominican Summer League team, according to just about everybody who was listening to Jeff Luhnow in the last five minutes. This gives the Astros nine minor-league affiliates (Pacific Coast League, Texas League, California League, Midwest League, New York-Penn League, Appalachian League, Gulf Coast League, and two Dominican Summer League teams).
In 2013, the Orioles, Pirates, Mets, and Yankees all had two Dominican Summer League teams, so it's not unprecedented.