[robterrell]

You've always had this ability, but with more convoluted syntax:

  osascript -e "tell application \"System Events\" to keystroke \"whatever\""

Specify the application too with multiple -e parameters. This will copy whatever is selected in Safari:

  osascript -e "tell application \"Safari\" to activate" -e "tell application \"System Events\" to keystroke \"c\" using {command down}"

[eviks]

How do you stimulate delays, animation intervals, key down/ups a with System Events?

[robterrell]

AppleScript supports the "delay" command. System Events supports both "keydown" and "keyup" in addition to keystroke.

[bestham]

Apple Script is a programming language and you have full control flow at your disposal to wait and branch as needed.

[eviks]

This is too generic to answer this specific question. Key down, for example, is not an inherent property of a programming language.

(and neither is delay precision guarantees, which might be important for some key sequences)