For those of you with the auto-hide feature enabled for their dock, here’s a tip found via AddictiveTips, that allows you to remove the delay time.
Just copy this code into terminal and hit enter
defaults write com.apple.Dock autohide-delay -float 0
and there you have it, 0 delay time for dock pop-up when you mouse over at the bottom of your screen!
To revert back to the previous setting, just enter this code into terminal and hit enter again
defaults delete com.apple.Dock autohide-delay