These are ideas from other MMOs, but they are used because they work to an extent.
Enchanting. Torchlight 1 already has it so it wouldn`t be contradicting at all for the TL MMO to include some of it. However I think it should do a little more than just add a couple of stats to your weapon 10 times. In Lineage 2, you can enchant your weapon to something like +15 and it gives it a cool glow. I would like one as such in TL MMO. It has to be done well, ofcourse. Now, about extending the gameplay. You don`t just get the best weapon drop and that`s the end of the game. You need to enchant several times with high risk to break it and start all over. In Lineage 2, there is a max amount of enchants, however that also means that how far you can progress is limited to +15 all high end gear. Raising the amount of enchants you can do on an item raises how much you can progress, but it also means that the player will be using exponentially more time the higher the max enchant + is because of the failure rate.
The problem that comes with this is that eventually older players will end up with uber gear while a player of the same level but unenchanted gear would be quite weak in comparison. Look at Diablo III, for instance. You hit level 60 cap on Nightmare and the rest of the character development is based on getting items that drop in Inferno act 1 to act 5. What some people do not realize is that they cannot just go through Inferno without first having that character development through those items. "Inferno seems stupidly impossible, nerf it!"
What Lineage 2 does is that instead of making 4 difficulties that are pretty much the same storyline, filled with the same maps, monsters, they make new content every once in a while. Actual content. Players then need to upgrade from their SS80 +15 new gear to SS99 and start enchanting it. Enchanting is a long process and it takes a lot of time and money. Meanwhile, newer players get a chance to catch up to them and gap between the uber max enchanted players vs newbies with no enchanted gear is null for several months, but eventually they will get all their gear to SS99 +15. What is wrong from the developer`s viewpoint is that they constantly have to make new endgame content. Which is sort of good for the actual players. Sure, their SS80 +15 max enchanted gear becomes obsolete after a period of time, but they can go to new areas, level up because the level cap was increased and they can start enchanting the new SS99 edition gear. There`s new progress to be made.
Edit: I will add, though, that a lot of content can be bad. Have you played Lineage 2? There is a LOT of content, it`s all cluttered up. There are a lot of options, you don`t even have the time to try them all. I think the newest expansion gives you quests that level you quickly from 1-40, but there are many old 1-40 quests and areas that end up being useless because who`s going to do them if you can quickly get the exp from the new quests? Also, they have gone so far that they`re undoing previous work they`ve done. Threw out the previous Talking Island, made a new village, new monsters, new areas in there. This isn`t exactly great in my opinion when a large portion of the game becomes obsolete and just lies uselessly around in there.