I seem to remember from Dstahl's interview on STOKED, that he wanted to have the entire solar system replace the one we have now and with an area that is without instancing i.e. Mars, Jupiter and Earth all in the same instance. I think that'd be great but can't see it happening with season 3.
In the mean time I would be very very happy with with any new ESD and love the idea of Klingons coming in and destroying it and we see a new ESD built over time.
It wasn't until I watched The Search For Spock recently that I realised you can't even see space from inside ESD as it's like a giant floating hangar. I can't wait to see what they're planning for the exterior.
The current interior will be positioned in the stem of the mushroom. If and when we add the interior docking bay viewing lounge it will be on a floor above the current ESD.
While I would love to see a new exterior what I really want is a new interior. No offence but the interior of ESD is the most uninspiring looking interior in the game and that is a shame since it is the main hub.