Avengers in 2012, Phase Two films in 2013 and 2014, Avengers 2 in 2015 three years after #1, Phase Three films in 2016 and 2017, Avengers 3 in 2018 three years after #2.
They probably aren't far enough along to confirm any of the individual Phase Three films. If they don't have a script or director or star attached to Dr. Strange, they'll keep working internally but not make a big announcement until next year when some progress has been made in development.
However, they will likely eat up half of the 2016/17 slots with Thor 3 and Cap 3, possibly GotG 2. Post-Avengers 3 when the main cast are finished with their six picture deals, Marvel will have plenty of time to tackle new characters like Dr. Strange, Black Panther, etc.