Background : This is borne out of game development and its long times on sync's and other operations which even on monstrous large hardware can still bring teams to their knees. Knowing the impact of what you are about to do is critical. Even more so when you close to deadlines. Knowing the impact means managing the impact.
p4 sync - normal p4 sync - no idea how long two seconds or two hours? shall I get a coffee? should I go to lunch? should I go home and come back tomorrow?
A possible wonderful tomorrow :
p4 -eta sync - first does "rough" estimate of how long the operation will take based on database size/is the database got locks already/number of files to add/delete ( i guess you could add network latency & bandwidth in). So based off the ETA you can say yes do it or nope ill do that later when its more appropriate.
Note : not expecting the timings to be hyper-accurate - but the concept is people can make a decision based on the estimate (small <5 mins , medium < 30 mins, large < 60 mins or crivens! > 60 mins). So they can manage their time better. And manage their teams time better by saying I am going to do a estimated medium command so expect slow performance for upto the next 30 mins-ish.
Its maybe some setting you can set in p4v so when you do certain/known heavy duty operations (sync/integrate/streams) it gives you a ETA. Training wheels for new users to perforce.. :)
If you could then put this in database so when you do a p4 monitor show it has the eta next to the user that be the icing on top of the cake...
not sure if this is a brilliant idea or the worst.... I guess your vote or lack of one will determine it...