I hate hearing this. Because it means 2 things:
1. I've just had to listen to a long boring rambling that wasn't worth the time it took to tell it...
B. I'm about to hear part 2 of said long boring story.
You see, people only say "to make a long story short" in order to break up a story that wasn't worthy of the length of time it was given in the first place. Maybe it's my ADD, but I can't pay attention to any story longer than a paragraph or roughly 74 seconds in length. Once someone breaches the perimeter of my attention span, I politely interrupt them and say "I'm sorry, but it would be rude of me to let you continue with this story when I'm actually thinking about something totally unrelated to what your blathering on about". I feel it's the polite thing to do. For the good of the land.
In the new world, claiming to make a long story short when really all you did was make a long story long will be a punishable crime.
AND SO IT SHALL BE WRITTEN!