As to the new teaser image...
link
I am pretty confident we are looking at a part of a movie sequence rather than in-game screenshot.
The apparent motion blur on the ships as well as the lack of crisp detail to the universe looks like a movie/cut scene. Furthermore distant planets on the sky box, as well as new planets and moons is just not realistic to expect for them to have redone all systems that way.
Also...none of us have a crystal ball but...
Reading the last few pages it's interesting to what people are hoping to see change from the X3 we now know.
I think it would be safer for people to keep expectations in check or you may be setting yourself up for disappointment by nothing more than your own over-active imagination. I don't see any revolutionary changes to UI, graphics assets, the universe, redoing models, etc. That would be a 3 year follow-up as X4, a new game, not an expansion. UI changes would be a massive undertaking but maybe with their hopes to get it to console, it may happen somewhat but very doubtful with 100's of functions UI is challenging to say the least. I see additional solar systems, additional ships, a new campaign. This isn't X4, it will likely be building on the current X3 game and it's existing assets with some new ones. It will be standalone which is becoming popular trend in gaming, meaning it will garner a full price rather than a expansion price, but I don't see this as anything more than an expansion, albeit a decent one I expect. With all the support that Egosoft provides with patches and free addons I have no qualms in paying full price for an expansion.
If history serves as an indicaor we will be seeing the game we now now with additions to the universe with minor changes/additions(minor in the large scope of the overall game world). But I don't anticipate any major underlying changes just more built on. Unless ofcourse they announce at the end of the year they decided to turn it into X4 and put more into it (it has happened before

). Sure it's all speculation but history should be an indicator and better to be safe than setup high expectations that will serve to only disappoint yourself.