Took about a month for the Herald to catch on:

New Metrorail line popular with airport travelers
http://www.miamiherald.com/2012/09/16/3006209/new-metrorail-line-popular-with.html

This line was the best thing MDT has done. It will prove to be very successful. It's a shame that's all we'll be getting anytime soon.

Post on the new MIA metro station. A ridership report to be released soon...

Miami Metro Orange Line inauguration
http://metroatlantic.wordpress.com/2012/09/03/miami-metro-orange-line-inauguration/

Orange Line's first month: ridership report
http://metroatlantic.org/2012/10/13/orange-lines-first-month-ridership-report/

Remember that it was only open for three full days in July when inaugural ceremonies where taking place, so it is not surprising that those 3 days had higher ridership.

There is an article in this week's Miami Today entitled "Airport's Metrorail Link on track to meet target of 800,000 users yearly."

The average boarding at the station is said to already be matching forecasts despite the fact that ridership is not yet fully developed at the station which will take six months to one year.

September ridership reports:
http://metroatlantic.org/2012/10/23/ridership-report-september-2012/

Agreed. We have to wait some months to really see how it does, I just thought ridership was going to start a bit higher. When I kept reading 7,000 and 8,000 daily passengers, I was expecting at least 2,000 daily off the bat. We'll see though, it's just starting off.

October ridership report: http://metroatlantic.org/2012/12/21/mdt-ridership-report-102012/

Metrorail ridership grew to an average 70,500 daily weekday passengers in October. The Airport/Central Station still showing low ridership with and average of 1,373 daily passengers.

November 2012 saw Metrorail grow to an all-time high in passenger ridership. 1.45 million total passengers and a weekday average of 71,800 passengers.

http://metroatlantic.org/2013/01/19/miami-transit-report-112012/