I have just met Sublime Text 2, but already like very much what I see!
I wanted to show you guys a little plugin I wrote to make the behavior of "duplicate_line" get closer to that of other editors/IDEs I was more familiar with (namely Eclipse and a few others).
So, here's https://github.com/malvim/sublime_text_directional_duplicate_line.
It's a command that enables the duplication of lines and selections before the current, as well as after (the current behavior).
I appreciate any feedback!