As much as I hate to say it, I might end up passing if the enchantment is watered down again like Oblivion. Cloaks, shirts, trousers on top of armour again please and no Azura's Star handed to you on about the third quest of the main story. Fast travel I can live with (I'm used to it now, after Fallout 3 and NV) even though I'd MUCH prefer Morrowind style travel (I want to RIDE on a Silt Strider, dammit).
So it won't be so much one single thing, but a repetition of all the things I found disappointing about IV which would make me pause and contemplate if I
really want to go through that soul-crushing disappointment again
Of course, I'll probably end up seeing screenshots of the landscapes and completely cave in again.