Some players have suggested that one possible solution is to make it such that dungeon mobs don't drop any loot or award XP. While this is a good start, it doesn't take care of the problem with botters in the open world areas. I think removing loot drops and XP from all mobs is a possible solution, but bots might still be able to exploit this system in some way.
Instead, I suggest another fix; require the player to solve a CAPTCHA puzzle before being able to use any spell. Templars, for example, would hit their Aedric Spear ability, but a box would pop up with a CAPTCHA puzzle they would have to solve before the ability fired off. This would also help with resource management issues, since Magicka would still regenerate while you attempted to solve the CAPTCHA. It could also help with the servers being spammed with client-side ability requests. Healing spells might need to be tuned up accordingly, but it would solve the bot problem quickly.
I throw my vote in for making dungeons/delves instances; not only would this ease the pain of bots farming bosses, it would also make it easier to get updates for quests that require you to kill (x) amount of mobs.
My boyfriend and I were working on Legacy of the Three out in Windridge Cave earlier tonight and it was such a pain in the arse to find and bind all 10 spirits because people were scrambling over each other like cockroaches to get to them first. It became so annoying that people actually started cursing and arguing with each other in /shout. We decided to relog in hopes of popping up in a less populated shard but to no avail - it ended up taking us 45 minutes to bind all 10 spirits.
I love ESO to bits and pieces and I'm willing to forgive most of the bugs and glitches due to launch pains, but I truly believe that public dungeons/delves is a terrible design flaw. They are breeding grounds for bots and discourse amongst actual players.