Seems like they'll reboot & recast most of the cast, but 98% of the casting thus far has been absolutely perfect. Potential "nobodies" replacing those we came to love will be rough. I'd love to see a push for animated Marvel movies, where you'd only have to get reasonable voices & can present stories that could never make it to the big screen (too expensive, too gory, too long, etc)...

I think they'll try and skirt the recasting as much as they can by focusing on teams and characters that are staying the same or starting totally fresh, like the X-Men and (presumably) Thor/Doctor Strange.

X-Men and FF being fully integrated into the MCU is the true "next big thing" after what we already have announced, so I'd expect that to be a focal point.