I'm very nervous about them saying they don't want you playing a "UI game" if only because that seems very broad. 2 things here:
1) Getting feedback as to how much damage your attacks are doing is critical to being able to play a MMO well. When they say they don't want numbers popping up, I get very antsy. Sure, numbers aren't everything, but I need to know what I crit for, how much attacks do, how to augment attacks as well as I can, etc so that I can play at the highest level I can.
2) They seemed to imply there won't be cast bars in the game? I hope that's not the case. For the sake of argument, let's say you're facing a mage of some note and he has two spells. One of these spells is a simple fireball attack and the other is a 1-shot ability. It is important for me to easily distinguish one from the other so I can interrupt the 1-shot and soak the fireball. Even while I'm typing this, this seems pretty obvious, so I'm sure that this will be explained later, but it is very important that information is given to the player via accessible and clear channels.
Combat will obviously make or break a game, but if you take tools away from a player that help him or her play your game better, you're not making it more fun... your just disenfranchising them.
Well on the first point im sure they mean the numbers wont pop up over their head , it will be on their health bar probably , they just mean its not like in WoW where its just numbers flying up , its immersing you in the world more which i think is great
Also the cast bar is replaced by animations which you will get used to in time but they also spent the second half of the last video emphasizing their are no one shot abilities , even the ultimate abilities
Looks like these guys know what they are doing when it comes to combat

love that you can use stamina to break cc so you don't just get stun locked or cc'd to death
