Well, since this is probably a sequel to PH, which was a sequel to WW, in which the King said something about living for the future, and Zelda said that they'd find "the land that will be the next Hyrule", I'd say it's going in the right direction. Sure, the King said that it would not be Hyrule, but would instead be THEIR land, but either way, he wanted them to make a new kingdom. Don't you think this ties in pretty well?
Maybe that's what the train is for - to commune with other civilizations and make the new kingdom thrive and become the Hyrule from another game.
Either way, don't dismiss everything as "omg this sucks" right away. We've done that in the past (or at least I did) with games like MM and PH, and they turned out to be amazing.
Don't get me wrong, I'm not trying to do that at all. (Maybe I worded it a bit negatively) I'm just questioning some design decisions. Moving away from Hyrule was a very brave thing to do. But it just feels like they went "Alright we have this engine, now let's make a boating game without boating." AKA a vehicle on green rolling hillsides. A Zelda game will stay Zelda, that's why I enjoy it. I just don't want it to become "Ride to dungeon A, beat said dungeon, Ride to story event, complete, Dungeon B, etc." But I have faith in the Zelda team.
Now to speculate like awesome Zelda fans:
The leaf thing Link threw in the trailer; Replacement for the boomerang? Maybe a Gale Boomerang like in TP? He retrieved a key with it and hit a switch, not to mention the line drawing to the target. It looks like some kind of leaf propeller. One thing that is noticeable though is that it only blows things in one direction.
Item option is gone, probably somewhere in Menu now. In it's place some kind of "Guard" icon that let's you move dudes around? Hopefully the puzzles amount to more than "Move dude over obstacle to switch, done".
A whistle icon is also visible; Maybe like Pikmin you can call the Guard off of whatever it was you told him to do at any time, which is great.
Also at the top of the screen in the same scene you can see a Safe Zone from the Temple of the Ocean King from PH. HOPEFULLY that is some new mechanic, because that was kind of a hassle in PH.
Also just noticed that the Boomerang is a separate item from the leaf blower thing, so hmmm.
Hyrule Castle from the distance actually looks a lot like the Hyrule Castle in TP. Still vehicle hearts so that means upgradable parts again? 4 different speed settings and a choo-choo button?
Stag Beetle boss is probably first boss in the game, being in the forest setting and all.
Also, the map screen when the train is in the giant green grasslands indicates that there is at least another screen to explore. Maybe 4 map regions like in PH?