As a new resident of Austin (Pflugerville to be exact), I wonder if the combined cities of Austin, San Marcos, and San Antonio could not support a major sports franchise. Especially with the development of 130 which will connect Austin to San Antonio (Seguin but it's near enough). The area is booming and, IIRC, the Marlins were even exploring the area as part of their search, which included Portland.
Round Rock has a AAA team and I believe San Antonio also has a minor league team. That's a fairly substantial fan base to draw from if you build a stadium in the San Marcus/Buda area. It was just a passing thought. Then again, it could be left over residue from the Dallas/Fort Worth pollution.