I know there are many other old school MMO fans out there that are hoping to see the fun pieces of an MMO make a comeback in ESO. For the youngsters let me list them:
PVP with FULL GEAR DROP
This could be done because the economy ran in such a way that gear was dispensable. Extremely rare gear existed but it was rare to the point that you knew better than to wear it in a pvp situation.
Forming a mob, tracking down evil players and killing them
Player Theft
You could steal from players. Sure it was impractical and you were GOING TO DIE most likely... but it was so fun that tons of people did it just for the hell of it.
Player owned housing (especially player owned vendors)
I don't want an instance of a house. I want an actual physical house that has to be purchased and travelled to.
Being a ghost (this was just hilarious)
Focus on Public Chat
I really don't understand when it became preferable to prevent people from communicating by hiding their chats somewhere off to the side in a UI, or having various channels. When you type text it should just be spoken for the world to hear (unless you whisper to somebody nearby). Sure this will be circumvented with voice chat... but in many situations it won't.
I think that the "drama" aspects that form from these sorts of game mechanics make it extremely fun for the more mature players. If ESO is going to let me play with like minded players i'd like to have some of these options.
Side Rant
Please don't make the same mistake which destroyed UO. Trammel. People complained that when they left town they'd get killed by other players and would lose their equipment, so UO separated the world into PVP and Non-PvP. They listened to an extremely loud minority of players and set up game mechanics that alienated their core user-base in order to accomodate them. No longer were people accountable for their characters actions or words and it was no longer as much of a society of players as it was a free-for-all in the pvp areas and a really boring game in Trammel.
The world should be fun, exciting and scary. You should have the possibility of being killed by players but it should not be overly difficult to recover and those players should be heavily punished. Only then will players actually form something like alignment-based guilds and begin to police eachother as well. The game would actually allow you to play roles...*holds back urge to swear*
Please, Let's see a real RPG here!