I'd say that depends on the story. I haven't played the original Rage, but I have played Far Cry 3 and this looks a lot like that in gameplay style. It's a wasteland, by definition there shouldn't be a ton to be found--though should still be plenty to see.
If I took a guess, transitions between major battles are going to be via vehicle and feature some sort of combat objective, maybe races? I don't know if I'd expect a loot system, that's not the general theme with Quake and DOOM games and, while this is neither of those, I think Rage would probably follow a similar path--they're just not collection games beyond serving direct purposes.
I would expect that a lot of was learned from DOOM in terms of keeping that down time interesting. It's not the same developer, but they're still under the Zenimax umbrella.
If the transitions are like the first game, you drive in between locations and get shot to pieces before you even arrive there. They made it so you only have one car, so you have to do races and other shit to unlock better weapons for the car before you can even leave to do stuff. Then you have to buy ammo every time you come back otherwise you run out.
Rage should be a linear game rather than a Fallout style game, probably.
The world looks like it has the same empty feeling. I like Fallout and the Elder scrolls games because there's so much stuff you can find, but Rage had none of that at all. Everything that could be found in the game was bought from a few different shops. I'm kind of getting the feeling there won't be any kind of loot system in this one too.
If the combat is better, which seems to be the case, how long is that going to be enough if the game has the other mistakes of the first one?