The subtitle for the original Lost Planet was "Extreme Condition". For the sequel, perhaps "Extreme Customization" might be more appropriate. Some really interesting details about Lost Planet 2's character customization have been revealed at the Capcom-Unity Blog. All sorts of different options are available for your soldier, including weapons, abilties, and, coolest of all, nicknames.
You can choose a preference to which weapons you'll find in game. Like the shotgun? Set the flag, and when you find a short range weapon on the ground, it'll be a shotgun. Maybe your co-op buddy likes flamethrowers; when he picks up a short range weapon, it'll be a flamethrower. That's an excellent idea, and one I wish was available in more games.
Each character will also have special abilities, though it's uncertain how these will become available. The blog lists an example of being able to activate a Data Post more quickly. This sense of specialization will be quite applicable to co-op games, perhaps even like an RPG, where each team member has a specific role.
Best of all are the nicknames. These are earned during gameplay, and function a bit like titles in an MMO. Say you use the flamethrower all the time, and handle it well. You might unlock a specific title, like "Toaster of Monsters" or something similar. For achievement lovers, these things will be totally addicting, I am sure.
Of course, there are numerous options for your soldier's appearance, as well. We look forward to seeing this in action when Lost Planet 2 is released! I'm hoping there's a "Monster Tonsil Collector" nickname, myself...