I don't think it will lose the buttons or headphone jack, it would be to big a gamble to use the Note 10 as a testbed for (or sd card for that matter)
I have a sneaky feeling that the s-pen will have a lot more focus than the few little bits it got on the N9.
If they get it REALLY right with cameras, bigger battery+faster charging they'll be nearly there with best 2019 device, 5G will be there but only because they have to do it, it really is an unnecessary cost at the moment but marketing will dictate it.
I would really like to see the headphone jack moved up top with the IR blaster in it again, it's a small thing but lots of people really liked it, FM radio chip as well.
Microphone in the s-pen would improve voice dictation in environments with background noise.
An external and optional but REALLY PRO s-pen must be on the drawing board as well, the way phablets and foldables are developing there is defo plenty of room for one and Samsung really do have the upper hand there.
I won't touch the subject of pricing except they need to be less greedy if they want to stay ahead of Huawei and that ball is in their own court