I usually say that something is not clear yet like "it is still in the wind" when something is uncertain.
Is there any English idiom or proverb that describe this saying?
The expression up in the air is a good example.
Depending on context, an alternative could be:
At a crossroads
crossroads (n.) a point in time when a critical decision must be made
We are at a crossroads and don't know which path to take as the potential results are uncertain.