Well, we cna make some guesses by extrapolation
Let's take COMBAT
The history fo combat in D&D has been one of simplification and streamlining. Thus -
1st Ed : Combat used a large, unwieldy set of tables.
2nd Ed : Combat used an awkward subtraction mechanic (THAC0).
3rd Ed : Combat used a simple addition mechannic.
4th Ed : Combat willl be so simple that there will be no dice or mathematics involved; attacks will be resolved using an encoded bar of Scratch-n-Sniff pheromones on the cover of the book.
SKILLS
Conversely, skills have grown more and more detailed through the editions.
1st Ed : Randomly roll a 'secondary skill' for the PC.
2nd Ed : Spend proficiency slots on secondary skills.
3rd Ed : Spends points on many skills, both primary (ie, directly contributing to adventuring) and secondary.
4th Ed : The skills system will be refined and 'de-grained' even more. There will be over eight thousand separate skills, from Climbing Trees, Climbing Cormyrian Embassy Walls and Climbing Plastic Rocks to Jumping Rivers, Jumping Sandpits, Jumping Sandpits With Bits Of Pumice In Them to Jumping Tall Buildings In One To Four Bounds.
Fighters will still get 2 sp/lvl.