"Cartel Coins", a new in-game currency, will be developed to entice players into enjoying weapons, armor and other unlockables through the microtransaction model. A majority of Facebook games utilize microtransactions incredibly well, so a company like BioWare, backed by EA, will surely have no problem making use of the often profit-generating system of transaction.
The main reason for going free-to-play is perhaps due to reports that the game's user-base is dwindling. With a glut of MMOs on the market today ("World Of Warcraft", "Rift", "DC Universe Online"), the market is divided. BioWare has been kicking around the concept of going free-to-play for a while, giving players access to the game until level 15, but now, with the level cap extended, players will be able to fully enjoy the digitally-realized worlds created by BioWare and Lucasfilm.
BioWare Austin has seen multiple layoffs in the months following "Star Wars: The Old Republic"'s release. With a bit of luck, hopefully the free-to-play model will be a boon for the company, allowing them to continue to grow. With backing by EA, BioWare has seen tremendous success in 2012 with the release of "Mass Effect 3" (even amid issues surrounding the game's ending), and is working on a new entry in the "Command & Conquer" series.