It's not going to happen but I think a discussion on it could benefit MMO's in general in the future. Feel free to discuss or add your own ideas and I'll copy it and add it the list. Remember this server would be optional. I have always enjoyed immersion mods the most in my ES games which is where I got most of these ideas from.

Weather: Cold, humid, warm and hot and nice cool regions. Day and night cycles. certain races do better in climates they are naturally use to.

Weight limit: Everything has an assigned weight value and race and strength affect how much you can carry. Equipping a visual backpack or bag increases carry limit.

Clothing and armors: When adventuring into snow areas you need to equip gear that will protect you from the cold. In hot or humid areas like a swamp, desert or tropical area you have to wear armor or clothing suited for that area.

Traveling: Semi-realistic traveling. Running slowly tires you bringing down the cap on your stamina and magicka bar, walking has no negative effects and slowly brings your affected bars back to normal. Resting by a fire for a couple of minutes replenishes the bars back to normal and gives a warmth boost. No instant travel. Ships and carriages are scenic, you will sit in the back of the carriage or on the ship until it reaches its destination. Ships can be attacked by pirates.

Eating, drinking, sleeping: Since, its a MMO I don't see a way to have sleeping in it without the use of phasing. It could be possible to do the day and night cycles with singleplayer and group phasing. Eating and drinking. Both can temporary increase regeneration of your bars and provide buffs to health, stamina, magika and disease resistance.

Camping gear: Players can purchase and craft camping equipment. Camping equipment helps player survive in harsh areas, by warming you up, protecting your from the weather and gives them a place to do simple crafting on the fly like, alchemy, skinning, armor and weapons repair and cooking.

Diseases and poisons: Diseases are long and detrimental debuffs that affect your character and require praying at altars or taking a potion to cure it. Some races are less affected by disease or poisons. Poisons are nasty and require an anti-venom PVP diseases/poisons would have their own system because chugging anti-venom and cure potions non stop would svck. In PVE certain enemies can poison you or give you a disease. Staying healthy affects the chance of that and using a potion or anti-venom protects you from being affected by them for a period of time so players don't need to spam them.

Traps are deadly: Yes traps will kill you if you run through them or aren't prepared. Thiefs and assassins can disarm and spot them more easily than others but strength and intelligence will let you see them to to a lesser extent. Traps in group or large group content would be much harder to spot.

Chest: Locked chest can be lockpicked or melted with acid which is craftable. Bashing works on some locks.

Horses: Zenimax is already doing a great job with horses. I would like to be able to tie them up places like to a tree, post or large rock and keep them in the world until I log off. Towns will have stables that are phased so you can your horse parked there. Sort of like how our ships stayed around in Vanguard.

As long as it would be a separate server, I'd have no problem with it. To be honest it's a good idea, just doubt it would ever happen .

Also,

I like the idea of melting it with acid or bashing. Wish it was something that could be implemented into TESO. Like if your lockpicking skill was high enough you could just bash a lock to open it, or if a lock was too high of a level for you, you could melt it with acid (assuming acid is hard to obtain, of course).