Well, that's a new twist. If the university is willing to pay the property tax on the acreage then it could just happen.
My guess: after the soil and groundwater clean-up the city will float the value of selling the land to developers - who will most likely perpetuate condo's and mixed commercial for higher profit (and higher proerpty taxes) and entertain SDSU's proposals only if the option to sell and develop falls short of tax-revenue needs/desires for the city.
One real estate guy I know crunched some numbers back in the higher-priced real estate market of 2005/2006. His estimate for local taxes on a mixed C/R zoned development on 166 acres in Mission Valley: Billions ... like 4 to 8 billion annually in taxes. Will SDSU be able to counter that?
Regardless, nothing will happen until the "green light" from the Department of Environmental Health when the fuel contamination is reduced to "acceptable levels". I think 2020 is a reasonable year to see some real manure hitting the fan blades in Mission Valley on many different fronts simultaneously. Sports teams, developers, taxes, and traffic gridlock.

If you thought Ringling Brothers and Barnham and Bailey was the "Greatest Show on Earth" ... just you wait. This will be a whole new Circus.
DC