It's not going to be different, it's just going to be refined. Here is the game in a nut shell:
1-Max Level content
End Game Content: Raids circa WOW Vanilla/TBC, "Heroic" Dungeons
PVP Battlegrounds, Arenas
Housing
Typical Crafting
New Stuff:
Paths - an extra layer of content on top of existing content. An interesting addition, but not really earth shattering.
Mod System - Circuit Board Crafting is kind of a combination of Diablo Gear and Socket gems. Might be fun. Might be frustrating.
Telegraph System - Take GW2 combat (soft tab target) and it becomes a hybrid of WOW and TERA. Toss in directionals to your attacks and you get telepgraph combat. Watch a video of it.
Essentially, from what I can see, the game will launch with a function cross server LFD system (not LFR). The are taking out the gear saturation and "easy of access" that made WOW feel very flat and ubiquitous that it is today. If you still enjoy a WOW like game with the normal stuff, Carbine seems to take the model and refine it feel like old school WOW but with more content, and additional systems that have evolved over the years.
I hope that makes sense.
TLDR: Modern day WOW 2.0.