I think they're being careful about promises, though I forget specifics about most of what I've read. There are things they've redone as the core of the game....suspension, graphics, tires, aero?, new tracks, new cars....then there are things they are very specifically saying may not be ready for release. I hope people pay attention to this note, weather, time changes, new AI, sounds, maybe some other things (again, I forget), he's specifically saying may not be ready. Don't get too hopeful.
Honestly, if everything they've already done (which I think is ready for July's demo) works as advertised and is kept for full release, I will be happy. Sounds, weather, time, AI....these things don't really concern me.
Also, some need to remember that this is a console 'sim' meant for the masses, not just dedicated sim racers. I believe this will always be the case for the GT series. There are real life based aspects of racing and tuning that PC sims will have and GT won't. Just like Project Cars...it's already suggested (in some posts in 'Other Games') that the PC version will be more 'sim' than the console version. This is just the way it is, IMO.