I suppose predictions can look a lot like a wishlist if you're not careful, but I'll be optimistic and call these predictions:
1. 2 career paths, offline and online
2. A-Spec and B-Spec are integrated
3. Ranking system for online career
This has really been rattling around in my head, so I'll spill it here.
So the offline career path would be similar to GT6 "career mode" area, except for the integration of B-Spec into most (if not all) events. Choose how you wish to complete a race, series, etc. Start a longer race or endurance race in A-Spec and hand over the car to Bob at a pit stop like GT4. Of course the game would distinguish how you completed the event, but for completion a gold is a gold whether done in A-Spec, B-Spec or combined (switching to Bob in the pits.) Doing it all possible ways would be a bonus.
Licenses should still be integrated into the offline career mode how they are in GT6. There would be license tests specific to B-Spec to unlock that functionality, as well as license tests aiming to train players for online racing.
The online "career path" area would only open after the player progresses so far into offline career mode. This would replace the GT6 quick match mode, except it would have more events. The events would be more clearly defined by skill level, but there would still be events that people could enter regardless of rank (see below.) The connection issues and penalty system failings would have to be remedied and I think PS4 could allow that. These events would be updated periodically like the seasonal events and would allow for PD-sanctioned online race series etc.
Online events would also integrate A and B-Spec. So in certain events, you could be in A-Spec going up against some guys' Bob, with him controlling it live. This might make sense for some types of races like endurance. Obviously B-Spec only races would be a thing, too.
Ranking would be key to keeping order in the online career. It would take into account your finishing position relative to others and their ranks, vehicle PP and penalties incurred. Some crazy calculation would rank drivers Category 1 through 5, with 1 being the best and 5 being a new/unknown. Start at 5 and work your way up. B-Spec Bob development would be similar to GT5, but I would expect it to be simplified (no XP or leveling.) Bob's would be ranked Cat 1-5 as well.
That feels better. Flame away.