User blog comment:Kacj321/Elder Scrolls Online: First Screenshot/@comment-193.242.122.4-20120507070126/@comment-86.129.40.198-20120507204130

I belive that it's to do with the number of players per server (see Battlefield 3 as an example of the disparity) and that a current gen console just can't deal with the stress of additional players and all of the problems that come with that. I could be wrong about that though.