Speculations can also be fun and if you're impatiently waiting like me, 2 months still feel fucking far away.
I'm pretty sure we will start out with a camp as well. Interested to see how much we can modify it, if we can camp wherever we want and how it works with other players, mainly the hostile ones.
RDR Multiplayer was good fun but also very limited. It didn't offer much in terms of ownership or customization and therefore I think the blueprint will be GTAO with a range of businesses being added along the way, free roam activities, garages stables, etc. We have already seen in the trailers that customization will be taking to another level with how you can engrave your weapons and hopefully we will see more smallish but cool personalized stuff like that.
It's sounds like the progressing system from RDR with ranks and legend status carries over. Hopefully there will be special items you can unlock all the way to (a realistic) max. level. Yes, let there be a ceiling instead of the endless leveling up in GTAO.