They did a great job incorporating the various characters (Punisher, Hulk, Yelena) in a way that didn't feel like just gratuitous cameos.

And introducing Jean as a bad guy before she joins the X-Men will definitely set up for the anti-mutant stuff down the road. I expect Metzger/the department of damage control to lead that effort, with the inhibitor that Spidey designed playing a big part. And I'm sure his guilt over designing that will play into his own story(ies) in the future.

Regarding the post credits scene...I wonder if it's gonna be bringing in one of the previous spider men (Tobey or Andrew) or if they're gonna introduce Miles Morales.

One thing that they glossed over...Banner figured out how to be smart hulk, but now he can't anymore?

And as for the X-men I also saw that they've cast Samara Weaving as Emma Frost