It turns out that the latest round of rumours has been right on the money. Fortnite's comet wasn't heading for Tilted Towers but Dusty Depot. So, Epic's Season 4 of Fortnite starts off with a literal bang but there's much, much more.
The trailer shows Fortnite's map altered by alien things although it's not Tilted Towers that took the hit. Also, Dusty Depot is now called Dusty Divot. It's now a facility surrounded with gravity stones, or as Epic like to call 'em Hop Rocks. Pretty fun, even if they are but a gimmick.
There's an additional location in the East part of the map called the Risky Reels and it looks pretty promising. It appears that Epic is indeed going to focus on the East part of Fortnite's map, now that the West has been taken care of.
Funnily enough, not being to destroy things on Fortnite's starting island seems to have bugged all the players and Epic did something about it. Well, everything but the bus, which is the only thing that can't be destroyed.
There are plenty of gameplay improvements as well. Headshots are prioritised when other body parts are in the way. Hand hitboxes have been shrunk a bit and you'll see the damage numbers when spectating. Also, if you force an opponent into falling, Fortnite will correctly attribute his fall damage and reflect it in the elimination feed.
Crossbow is done for, most probably because it wasn't really all that useful. Initially promising stealth and all, it never grew to more than a gimmick Fortnite weapon.
Epic went all out when it comes to cosmetics as well, introducing sprays and allowing users to better arrange their Fortnite gear. You can mark cosmetic items as favourites and even randomize your look from your existing gear, which should provide for some hilarious looks if you've got to cash to burn.