There doesn't seem to be much to it other than shooting the various creatures that inhabit Pandora, though you are able to bring experience and loot, including Moxxi's Rocket Launcher, back into the core game. So, unless you are a completionist, I wouldn't worry about needing this content.
You know what would have been even better for the game to include? A pleasure dome.
Gearbox details process for importing saves into the Borderlands Handsome Collection
8:00 AM on 03.18.2015
Borderlands: The Pre-Sequel's Claptastic Voyage trailer shows glitch guns, confetti
9:30 AM on 03.11.2015