You just can't tell how much time it takes to finish the block download!
We're not interested in time guesstimates, but in progress. Right now, progress is shown starting from the genesis block, but it would be much more useful to show it starting from the last downloaded block before syncing started.
Okay, I really thought you wish a time-left based approach ... I took another look and think about integrating a display option for switching between absolute and relative progressbar display. I'm not sure if I get an core developer ACK on this though.
Dia