1) Stamina based combat seems very amazing. Very similar to Oblivion and Skyrim combat, but with all the details and strategies of an MMO. I hope they do it right.
2) Truly open world. They say its going to be open...and I hope they're telling the truth. If I want to (and am strong enough to) I should be able to stroll from Windhelm to Mournhold. Hoping its a truly open world, and not an "open" world.
3) Instanced player housing and guild halls. I spent a lot of my time in Morrowind, Oblivion, and Skyrim in my house. I want to be able to display trophies, relax, and use services (mailbox, crafting, etc...) all from my very modifyable house. This is a huge part of TES, please make it happen.