[crazy1van]

> it's a guess and can never be anything but a guess

Of course it's a guess. The question is how to make more accurate guesses.

[dragonwriter]

> The question is how to make more accurate guesses.

I think the question should be about how to maximize the net return on time dedicated to development, which may mean spending less time on (and investing less reliance on) estimates rather than expending unbounded effort improving the quality of estimates.

[satyrnein]

What's the value to Sales/Marketing/etc of knowing what's coming when? How do you estimate that? It's estimates all the way down!