That being said, there are a few things that could happen for the second one. And assuming the stories of moderate success for RAGE with a small team are true then I'd like to take the internet as a soapbox for a moment and shout them out.
"Dungeon" design: "Rage isn't a corridor shooter" oh but it is! When you get into a normal combat area it is. Ok, its not like most other "big name" titles do any better. But that doesn't mean it couldn't be better than it is, the first Halo comes to mind in terms of level design; and a lot of other things when it comes to campaigns for an fps game. But larger areas to shoot baddies, giving the player a good amount of room to manuever was great. Rage feels generally too restricted when it come to where you can move around too when shooting the gamut of baddies thrown at you.
And while we're at it, another design ID could borrow from is Fallout 3's. RAGE is a bit of an open world/rpgish type game, or so it seems to me. Having dungeons be less of a "flowing corridor" and more of a "place you roam around in, picking up loot, finding baddies and interesting odds and ends" might make the entire thing more interesting and engaging.
Speaking of more interesting and engaging, some more environmental interaction in terms of combat wouldn't hurt. Bullet penetration through thin materials, water you could duck down into (and maybe even follow physics and have bullets shatter upon entry!). Some destructible cover, more ways of killing baddies maybe? Steam or gas pipes that burst out flaming/scalding jets when shot? Or giant cliffs and pits for enemies to fall off when they stumble from being shot.
"World" design: Flowing naturally into this is world design. Less invisible walls damn it! Wellspring was so utterly detailed in ever way that I sort of just wanted to hop about it, looking all over. Less arbitrary invisible walls would help. While you're at it, give players something to find while they're hopping about willy nilly. It worked well in Borderlands, so why not here? Throw a gun upgrade in an odd sidepassage, a hard to get ammo type up on a roof. Instead of blocking a player from getting to somewhere it appears they could, let them get there and then give them a motivation for doing so!
And while we're on the subject, why not have some random interactive things that players can just... interact with? A silly thing it would seem, but RAGE is a little silly at times. Flush toilets, shoot out lightbulbs, kick chairs. Why not? "Open World" type games should generally feel "alive" and that would go a long way towards it all.
Speaking of an open worldish game feeling "alive", well a day/night cycle REALLLY helps with that. I know I know, 60fps on current gen consoles didn't get you there in terms of power. Especially not with the targeted visual quality. But RAGE 2 on the next generation of consoles, ahh there's a different story! I know, maybe not doable with the exact quality of the entirely precalculated light of RAGE, but no doubt something excellent can be worked out, and with far less compression blurriness.
"Mission" design: This is perhaps RAGE's biggest fault, and here's why. The missions aren't really structured around the fact that you sort of have an open world out there. As a player there's little to explore and find on your own. Little in fact to do on your own without being specifically told to do so. And doing just that, going off and doing things for the heck of it and then being rewarded, has always been the "open world" type of games biggest strength.
What I'm saying is, there should be interesting things the player can see just wandering around. They should be able to stop and get out and explore these interesting things, engage in some combat, get a reward and etc. There needs to be some kind of, sandbox to the entire thing. Bandit patrols that wander around sure, but trader caravans going through and battles between the two. Maybe a choice as too which side you wanted to join, and appropriate rewards for success thereupon; or even punishments for failure if you survive!
Well, that about wraps up what I've thought of. Except for one last little bit. RAGE is gorgeous, no doubt about that. But in terms of art direction it sort of feels like "Mad Max to the EXTREEEME!" and, well that's what every other Post Apocalyptic game has done. Borderlands (1 anyway) is "Comic booky Mad Max", Fallout 3/New Vegas is "Cheesy 50's Mad Max". How about, instead, going for a cross between "Dry Desert" Post Apocalyptia and "Earth After Human's" AKA "Film adaptation of I am Legend" Post Apocalyptia. Have a desertish area that's still got life in it, maybe even pretty places in some cases. Ruins overgrown with weeds, gnarled dry trees sticking up through old roadways, etc. Sounds good to me anyway.
