Difficult question, but you shouldnt directly compare it to WoW. Actually theres not to much known about top-end-gear. But there are different systems influencing it ...
Top level will be 50. But there are already announced veteran levels. Those are to be said 10 of them. With some equipp require having veteran levels. Same goes with instanced dungeons. There are heroic/challenging/veteran modes of dungeons. The first ones require vet lvl 1 and later ones even require vet lvl 5 or 6 (not shure about). Additionally there are areas called 50+ and 50++. (Those are the vet level playgrounds. Basicly those are high lvl versions of the other alliances starting areas. The first area you want to move in, becomes 50+ and laters you can enter the left one too at 50++.)
Raid/battlegroup size is 24. For pvp (or ava in teso) this is too small. So there are probably raid instances. But theres nothing known about loot and items from there.
It was announced, that crafting might/would/should play an important role on top end gear. If you look at it, every crafted item could be upgraded to legendary, if you could find enough refinements (upgrade ingredients.) Since those were not based on the item level, it might be possible to farm those on world bosses for them. (You have a chance on those components, when you break down/recycle items of the matching quality. To get legendary refinements you have to recylce/extract from legendary equipment.) Additionally you can craft items with set bonusses, if you find the right working place for them. (The sets I ve seen so far, always had three items and you can choose when crafting, which ones those should be.) What i dont know, is , if there are additionally raw material tiers in the 50+ and 50++ areas.
On top of that you will have a way to equip your char via pvp. It is announced, that there will be no difference between pvp and pve equipp. But there also is no need to do pvp to get the top equipment.
Aside from that, there is some kind of diminishing returns on stats and other traits. (I still havent fully got into it, but if you concentrate on one stat only, you will do way worse thatn you would do splitting traits up.) That way it might not work like in wow, where only concentrating on getting items with the highest str for a str-based char would be the way to go. (pls no discussion about ... i know, that even str -based chars might go for crit or mastery or whatever better atm, but its the principle i am talking about ... *g*)
