The crafting profession subsystem in SWTOR is very different than the one in WoW, and it will be interesting to see how it plays out.
A character in SWTOR can have up to three professions or "crew skills". There are three types of skills: crafting, gathering, and special professions. So the obvious pattern is to take a crafting skill and then take the gathering and special skills that compliments it. The gathering skill gives the materials to make green items, while the special skill gives the materials to make blue or purple items, as well as gifts for your companion. There is an additional special skill, Slicing, which essential gives money and schematics.
Crafters can reverse engineer the items that they make and that gives them a chance to learn to make the higher rarity version of the item, as well as some of the raw materials. For example, reverse engineering a green item gives a chance to learn the blue version. The blue version is better than the green version and has the same level requirement, and uses the same type of material to create.
For example, my Imperial Agent has Cybertech as her crafting skill, with Scavenging as the gathering skill, and Underworld Trading as her special skill. Scavenging gives the materials required to make green mods (items like gems). For example, I can make and use Green Skill Mod 10. Reverse engineering Green Skill Mod 10 gives a chance to learn Blue Skill Mod 10. Blue Skill Mod 10 probably has the same stats as Green Skill Mod 12, but Skill Mod 12s require level 29 to use, and I'm not at that level yet. Blue Skill Mod 10 also requires some materials from Underworld Trading.
So if you keep your crafting up to date, you gravitate towards using the blue mods in your personal gear, and making green mods to level up. If you're behind on crafting though, you'll probably just make green mods to catch up.
In any case, the key innovation in SWTOR's crafting system is the introduction of a new material: Time. It takes a certain amount of real time to craft an item. At the beginning, it's only a minute or so, but the time keeps rising. Right now, it takes me 15 minutes or so to craft an item, and I imagine that the time will increase to hours or possibly even days.
I've mentioned before that there are four elements to crafting: gathering knowledge, gathering raw materials, transmutation, and using the created item. In WoW, transmutation is a negligible element. In SWTOR, transmutation is a vital element that has to be taken into account.
The way this works is that your companions who remain behind craft for you while you adventure with your regular companion. You tell your droid to go make a skill mod, continue questing, and then the droid announces his success or failure 15 minutes later.
The reason this is so important is that it puts a significant constraint on the supply of items. As well, it's very hard in WoW to make a profit in crafting because the buyer often supplies her own materials, and the crafter is expected to make do with just a tip. Or have guild crafters who do all the crafting for free.
For example, after my raid the other night, I did enchants for four or so people and cut gems for another person. It took maybe 10 minutes to do all that, and most of the time was coordinating the trade as they gave me mats, and then I gave them the enchant.
In SWTOR, it's literally impossible to do that. Even if they gave me mats, I'd have to queue up the crafting, and it might take several hours for it to all finish. This means that the buying and selling of crafted items will move entirely to the Auction House (or Galactic Trade Network) marketplace. Which means that people only purchase finished items, not raw materials, and that prices will float and a profit can be made from crafting.
It is a very intriguing system and I am greatly looking forward to see how this all plays out.
But it does bring us to the greatest weakness of the SWTOR crafting system, and that is the fact that the Auction House interface is pretty terrible. It's worse than WoW's default AH. Something as simple as a price check for an item you want to sell takes like five steps. Select category, select subcategory, search, type in the name of the item, then filter the search. Repeat all the steps for each item you want to sell.
The SWTOR crafting systems needs a fully functional Auction House to reach its full potential. If I had one suggestion for the SWTOR crafting devs, it would be to take a look at the WoW AH mods that the serious goblins use, find the one with most usability, and copy that. Pretty much anything will be a significant upgrade over the current interface.