Season 1 did a good job of Barry gradually discovering and developing his powers, learning to run faster the longer it went on, and slowly beginning to master his abilities with help from Harrison Wells, Cisco, and Caitlin. This reached its peak when he was able to run up a building to prevent a black hole, and run so fast he travelled back in time. Now it has shown that, it needs to keep on growing those powers and showing that Barry can control them even without the help of Wells. It can certainly build on the notion of time travel, and have him running even faster, especially if there are to be other speedsters introduced (Barry is supposed to be the fastest of them all). One new ability has been announced, although they aren't saying what it is. However there was a tantalising hint from Grant Gustin, who said that "it involves lightning." What that could be remains to be seen, but it sounds very exciting, and will hopefully contribute to a larger development of his powers and exploration of the Speed Force.