The 400-foot extension of the runway at the Roseburg Regional Airport is good news for pilots landing jets there, but what does it mean for the rest of the population. Could we be closer to a time when commercial air service might be available from Roseburg? Are we going to see a business boom because of the increased access? Airport Director Mike Danielle says he fields such questions frequently. Answers to both depend heavily on the economy. When it’s profitable for an airline to serve Roseburg, one will arrive, Danielle said, but he warned that other cities have found it …