Well, i've been playing MMO-RPG's, for almost a decade. And during this time, i've tried out the majority of them. I currently have only been playing World of Warcraft (WoW), and Neverwinter. I've also played, and greatly enjoyed Oblivion and Skyrim (I gladly burned out my last laptop on Skyrim, lol, it might even be my favorite 1 player game to date), so I just thought i'd give a suggestion.
World of Warcraft has been around for quite a while, and i've played it since Vanilla. But here lately, the devs of said game, seem to not care about balancing things out whatsoever. Certain classes are just laughably superior in every situation, and world PvP has been taken over by the PvE players, due to horrible itemization design.
To make matters worse, the Devs don't really seem to care what the player base has to say about any of it, and delete all threads on the forums that cover the many imbalance issues, that apparently will never be corrected.
I'm just hoping that Elder Scrolls Online will pay close attention to PvP balance (sadly, I don't really play MMO's to raid / PvE). And perhaps consider pushing back the release date until some months after World of Warcraft's newest expansion is released.
When Warhammer Online came out, all of my friends and I, back in the Navy played it. The PvP aspect of the game was in our opinion, superior to World of Warcraft's, so we all played it for a few months, but the game as a whole just felt kind of rushed, and more like it was in a Beta or even Alpha stage of development.
I believe that Warhammer's biggest mistake, was rushing their development, in order to try to beat Wrath of the Lich King's release date. You can't steal WoW's playerbase by releasing before an expansion, especially with a game in a Beta state. Needless to say, every single one of my friends stopped playing Warhammer, roughly around the same time.
Star Wars failed because there wasn't enough for max level people to do apparently, so all my friends left for that reason. I personally left it, because I didn't like the PvP, I only liked the character's well written story lines.
The game itself has potential (and quite a new and confusing talent system), and i'm just hoping that the game would come out after WoW's Warlords of Draenor, since true gamers are going to buy both anyway, make a comparison, and play the one that they like more. But, WoW has a weakness, max level gear grinding for PvP or PvE takes 2-3+ months, and once you've done the weekly things (raid, Conquest, Valor), there's almost no point to play until the next week.
The other real reason i'd like the release date pushed back, is because of WoW's history of taking what they like from other games. For exmaple, Achievments were only released because people liked them in Warhammer Online, and the AoE Loot system was only added because it was a very nice feature in Star Wars: The Old Republic (or the TOR-Tanic, as me and my friends now call it).
I'd hate to see WoW take what they like from ESO, and add it into their finally declining world (mainly due to imbalances, pandas, and now unstable servers).
And I know that it's probably not your intention to beat out WoW or anything, and you probably have a team for balancing things within the game. But there's my 2 cents, sorry for the wall of text.