Why stop at that number. DFW is American's largest hub and is just one stop away from most cities east of the Mississippi. QANTAS could divert much of the North American traffic that currently requires two connecting flights to DFW and require just one connecting flight. DFW has a brand new international terminal that is mostly empty. LAX is very close to capacity. If the DFW-SYD flight works out, why not add a DFW-MEL flight? With the addtional range, MEL-SFO should be easy.
Delta abandoned DFW as a hub because it was far more expensive than hubbing in ATL.
The DFW international terminal is really nice. I started using it as a quiet area last summer when it first opened.