The CW can do any number of things next season, especially considering they need room for new shows and possibly iZombie despite renewing all their fall shows. I can tell you that Arrow, The Flash, The Vampire Diaries, and most likely Supernatural will be keeping their time slots. Some shows that may possibly be moving:
The Originals, which has really sunk following its move to Mondays, could very much move to Thursdays at 9 after its parent show, The Vampire Diaries. The latter can no longer launch a new show, even for The CW’s standards, and Reign looks too weak to be on the fall schedule. However, it has helped improve the network’s Monday ratings, and is unlikely to do better on Thursdays.
Reign and The 100 both look summer bound due to their very low ratings and the fact that the network can only schedule nine non-reality shows in the fall.
Jane The Virgin, which saw a brief spike in the ratings when The Voice went on hiatus, has since fallen back to its prior levels on Mondays. I think that The CW may be considering moving it to Fridays, as Hart of Dixie, another heavily female-skewing show, thrived on the night. I do not see a Friday time slot being a downgrade for the show. Of course, keep in mind that at least one of the two shows currently airing on Mondays will stay there.
Well, that was quick! There you have it!