it’s up in the air 尚未确定；尚未决定；悬而未决

【例句】
It's up in the air so far.
这件事情到目前为止还悬而未决。

Are you sure you are going to set us up? 5. Probably. It's still up in the air.
你确定你要帮我们制造机会吗？大概吧。但还不确定。