The best realistic options for the ACC are TCU and/or SMU. No school is leaving the SEC or Big 10 to join the ACC. A major university in DFW makes a lot more sense than WVU, Cincinnati, a service academy or a directional school in a state where we already have two of the three major universities.
TCU is the most attractive of the remaining Big 12 schools since it is the only one in a major metro area. Lubbock, Waco, Stillwater, etc. are not attractive locations with large population concentrations and convenient transportation options.