I don't have an opinion either way, but it feels like Apple walked away from iOS 7. Hmmm, I guess I just had an opinion and it's, "no". 🙂 But iOS 8 is still a ways off and anything could happen.
I would suspect they will to address the calendar bug deal and a few other issues. The fact that the 4s is the oldest iPhone iOS8 will support I would think they would address those bugs and release 7.1.3 for older device users. But who knows. They could use that as a reason folks need to upgrade to a newer device too.