I'm sure that many people might have already talked about this, but in the middle of the roundabout there's a rectangular silver plate on the floor. If you look at it, it says (I might be wrong in the number) "Rex Regis Lucis Caelum CXIII". It's probably nothing, but could it be his tomb? It certainly has the shape, although I guess it's kind of an odd place to bury someone, ESPECIALLY as he's not the only King Lucis has had (or will have, if Noctis continues the legacy).
Anyways, it's pretty obvious that Regis either dies or the rest of the characters think so, at least for a while (the ED ending, for example), so even if this is true, it's not like an unexpected twist or something has been ruined.
But as I said, it's most likely nothing (I can't provide pics for the former right now, but yeah).
Also, in the JP trailer:
(1:18). For a moment I thought that was his father's body, but it looks like it's a Niflheim soldier. And it really seems that we might return to Lucis sooner in the game than I expected. That'd be pretty cool, I really want to explore the inside of the palace and, especially, some districts of the city.