This is an idea I've seen on the forums that could make a great expansion. Companions are an important part of the game, and for the players that like to get attached to their characters and their character's companions a major update to the current system would help a lot of people become more immersed in the story and care a lot more about their companions. An expansion for companion characters should include most, if not all, of the following features:
Expanded companion storylines. Like the crew skill expansions with 2.0, extended storylines can be bought as a legacy character perk for Credits or Cartel Coins. They could touch on the player's bond with the companion, add to the companion's backstory, how the companion and the player feel about their missions, and most importantly, touch on the stuff that players wanted through the regular companion chain (E.G. Ashara Zavros accepting her role as a Sith or Lord Scourge converting to the light side through player choice in conversation)
The ability to talk to companions outside of the companion missions, like KOTOR. When you click your companions, the camera will (quickly) pan to them, and you can choose from several options of what to do or say, like a regular conversation in SWTOR. This might annoy some players who accidentally click their companions while fighting an enemy or trying to click something else. This could be avoided by disabling companion conversations during combat and adding a toggle for those who would prefer to avoid this completely.
Pazaak. Players can play with each other and collect cards for their deck through missions, operations, flashpoints, and warzones, after buying a starter deck from an NPC on the fleet who will also teach you how to play. Companions will be able to play Pazaak as well, and be given their own deck, or use a copy of the player's deck. A practical purpose of playing Pazaak with companions could be to act as Pazaak training dummies, while exchanging dialogue and gaining or losing affection along the way. Rewards for playing Pazaak should be good, but not too good, so players don't play Pazaak to gear for operations. Staking credits could be a possibility, or a rewards shop that trades "Wins" for cosmetic gear and credit cases.
New, side-story-related companions. Semi-important characters such as Thana Vesh and Lemda Avesta can join the player assuming they are still alive through a quest chain similar to the HK-51 chain. The ability to access the quest chain will be given to the player via Legacy Perk; players who did not kill the character will have the Legacy Perk unlocked automatically after the mission's completion, while players who did will be able to purchase the Legacy Perk for Cartel Coins or Credits. The Legacy Perk applies only to the current player-character.
SGR implemented with companion characters. Bioware has said this would be difficult to do considering the amount of new love triangles that would create. To make it easier the new love triangles could be implemented later. The basic same gender romance on release would play out regularly as it would opposite genders, with minor he/she and him/her tweaks along the way along with any necessary animation changes. The full version could be added over the course of more updates.
The ability to purchase a repeat of a companion storyline. Players that want to repeat their companion's mission series again can purchase a voucher from a new salesperson in the Cartel Bazaar (Memory wipe?). The voucher can be purchased with Credits or Cartel Coins.
Companion weekly missions. Going back to realistic conversations with companion characters, once a week they will ask you to help them with something or do something together. For helping them you will get credits and experience equal to a weekly mission of your level.
Expanded companion side quests. Most of the player's companions all come to a point in their storylines when they ask the player for some time away from the ship. This point in the story would be expanded so that a player could have the option to join them on their mission. Some companions already have this feature, mostly the first companions the player starts with, but side missions like these could add to the story and help the player bond with their companions. (Suggested by Allronix)
Companion combat role kits. Similarly to companion customization kits, these can be bought from companion vendors around the galaxy. These kits can be equipped in a new equipment slot to your companion, and will change their role, abilities, weapon and armor proficiencies based around their similarity to player classes. Combat role kits come in either Melee Damage, Melee Tank, Ranged Damage, Ranged Tank, or Heal varieties. (First suggested by morfius)
More lively companion behavior onboard your ship. Companions could be able to walk around your ship and interact with other companions, having casual conversations or playing games with each other. This would help both your ship and your companions seem more alive. (Suggested by Shissan)
RotHC included a new planet, a new operation, and a new level cap, along with other features for only $10. This expansion could easily be sold for at least the same price, and could be sold for even more with fully implemented SGR from the main update, a new flashpoint chain (Like the Revan, Rakghoul, and Czerka FP chains), and maybe a new species or warzone.
What do you think?