International users know there are hours to ask StackOverflow question that are better than others, namely during workdays when the US is awake. In these times the responsiveness is much better. I think it would be very helpful to know how many users are currently logged on, which could be served as an estimate to how quickly an answer will be provided (everything else being equal, that is).
To clarify:
- If I have an "urgent" question I will probably not wait with it
- I understand the "positive feedback loop" problem that may occur, i.e. that people will less and less participate during the less responsive hours, however I believe transparency to the data is more important.