I think 8.25 will continue to be the industry choice of size and it's a good size if you wish to do all kinds of skating (transition, tech, handrails, etc.) on 1 set-up.
I think the smaller boards wave is lowkey upon us, but it's more of a personal preference thing. Not something that the vast majority is trending towards. It seems people want to to run bigger wheels and wider trucks. Mark Suciu is one that comes to mind, he was on 147's forever, but now he runs 148/149s with bigger/wider wheels. P.Rod also made the move to 8.25 a couple of years ago