I came across this question on meta recently: Make the New Answers to Old Questions real time
It got me thinking: why can't newer users see new answers to old questions alerts (10000 rep required)? As Stack Overflow becomes full of good general questions, I think the scope for good non-duplicate questions is decreasing. A lot of the good new material may well be in the updates to old questions: new ideas of how to do things, or new methods becoming available or required as languages change.
Allowing the average humble member to see the action on old questions may well allow us to be involved more in exciting progress with the various languages and could reduce the number of duplicate questions being posted.