The multitiered arena idea is GREAT! I know they kinda copied DOA, but if I'm not mistaken, MK3 had the multitiered arenas idea, so I don't think EB is copying anyone really.
As for the look of the arenas, I have to say that they look A LOT better than in MK:DA. Everything looks pretty dark so far, which is cool. The arenas with the hanging bodies looks great, and the arena with all of the pillers definitly looks cool. Gamespot said something about it being a church or something like that. Definitely cool.
Couldn't tell much else from the pics, but with the environments being interactive and multitiered, as well as return of stage fatalities, I gotta say that the arenas have never been better in this series!!
Whoever made the observation that MK:D is to MK:DA what MK2 was to MK1. I definitely think that you're going to be right about that. If that is the case, we're in for a realy awesome gaming experience!!