The pillars of this are:
1. Trinity class focus. Instead of the more open ES skill system we'd have your "healer/tank/dps" and then the combat and groups built around this expectation.
2. "Theme park" world. Basically hand holding, the world is designed to "funnel" you as a player through avery very set linear path mostly, with zones/area's built for "x" lv only, where if you explore (which is one of hte MAIN things people love about TES, the freedom to explore) you are punished by this design, basically the sense of exploration is greatly diminished from that design of a world.
3. Combat, in almost any mmo combat works like this. You click a mob, auto-attack, then spam your specials (the skills you learn when you lv up). No real strategy, not fun, and it becomes EXTREMELY formulatic, for anyone that has played an mmo you know what I mean. You get to know your skills, you know what skill in what order works the best for dps and every fight basically boils down to repeating (with no strategy) the same formula of keystrokes over, and over, and over, and over. Combat isn't fun, it's not kinetic or anthing.
I hope they keep the TES "feel" alive as much as they can. This means a world that feels OPEn and FREE, where you can explore it, at your own perils and find interesting things to do WITHOUT having to "stick" to your pre designed lv-based zone only. Character wise you should have freedom, not be stuck into ao certain "class" type nor should group play be built around the "Trinity" setup, where you need a healer/tank. There is a REASOn that healers are generally the least played classes in many mmo's, it's not fun (I know it is for some) but for most people it's just not a fun thing to do, this leads to the old /s "LFG need healer" for 30 minutes just to do a dungeon, it's not fun and is just time consuming.
TES online needs it's freedom, that is what TES ia about to me in it's most simplest form, freedom. Freedom to explore, to build your character, to write your own story an dplay how you want. Good, bad, the guy with the gun ok ok not that but still
