I checked UTA's Frontlines 2015 page
Airport Line (westward branch at Arena): construction continues. Should open in 2013
West Valley Line (southwestward branch at Central Pointe): construction nearing completion. Should open Aug 7 this year. Trains will go from there to the University line.
Mid-Jordan Line (southwestward branch at Fashion Place West): construction nearing completion. Should open this year or the next. Trains will go from there to the Arena station. When the Airport Line opens, will the trains continue into it?
Draper Line (southward extension from Sandy) : construction in initial phases. Rail and ties from the old RR line now gone, utilities now being relocated. Possible completion date: 2015. This extension may eventually be continued further in that old rail line.
Sugar House Streetcar (eastward from Central Pointe): still in planning.
Frontrunner South: construction continues. It should open by 2015. It will have its own track, east of the existing UP track north of Sandy, then over that track on a flyover bridge, then west of that track south of Sandy. That flyover bridge is essentially done.