First of all, it looks great, just visually. It's got a sort of stop-motion feel to the CG, like the Lego Movie, which worked really well there and might just as well for this considering it's more comic-oriented art style. I like the colors and the motion blur on stuff like the subway train. So no complaints there.
Storywise, it's pretty obviously got Miles Morales as Spider-Man this time, and his story might be a direct adaptation of Ultimate Comics Spider-Man, seeing as how he walks up to a grave that's probably Peter Parker's.
He can't have been Spider-Man for too long, because his suit looks like he just made it, what with the kinda slipshod spray paint spiders on it.
He's chasing someone who appears to be the Prowler in one shot, so it being a mostly unchanged Ultimate Miles Morales makes sense.
But now the baseless speculation. At the end, he's talking to someone in the subway, and says, "Wait, how many of us are there?" I'm gonna make a guess here and say that's Peter Parker from an alternate universe, like Spider-Men. Given that the title is the same as the universe-crossing Spider-Man story, it's possible they're combining Spider-Men and Spider-Verse into one movie, where first Miles meets the regular alternate Peter Parker, but eventually it leads into some universe hopping adventure.
When it shows the title, you see flashes of different spider symbols, like one where it's a heart with legs coming out of it, or the traditional logo, before getting to Miles' spray paint spider.
If it turns out the film's going that route, I would honestly be surprised. In a comic this would make sense, because comics always have that alternate universe shit, but in a film it's a lot less prevalent, and probably a little risky. That might be because Sony Pictures is making this one, instead of Marvel like Homecoming. At any rate, I'd love to see more standalone films like this, like say, perhaps a Spider-Man 2099 film? I can dream.