We knew this was something WMATA had been considering for some time, especially with the agency’s big push toward emphasizing universal adoption of SmarTrip cards, but today it’s official: Metro is eliminating paper transfers in January. Beginning January 4, 2009, only bus riders using SmarTrip cards will be able to take advantage of free bus-to-bus transfers and discounted rail-to-bus transfers. Bus drivers will no longer hand out paper transfers, and machines that dispense paper rail-to-bus…