All of those have been revealed with PC graphics except RAGE and you can't really compare RAGE with Skyrim's environment because they are completely different. Skyrim has vegetation everywhere and RAGE is barren. But when it comes down to models, Skyrim looks better. Also, I've never been the one that said "you can't do it because it has too much stuff" because that is a bad argument.
They released videos of what Crysis looks like on the 360 and PS3, go look them up on youtube. That was crytech that released those videos.
Vegetation usually doesn't create THAT HUGE of an impact on the game's possible graphics. And while Skyrim's models look good, I'll have to disagree with you there.
Technically, that's not Crysis though. That's some demo levels of Crysis remade in Cryengine 3 and then compared to the same shots at different qualities in Cryengine 2. So technically, it's Crysis 2. Or even more technical, it's not Crysis at all.
Also, everyone else please look at my previous post. I edited something into it that might clarify some things on this "Open World = Not as impressive graphics" thing.
The Witcher 2 was never on the Xbox 360 or the PS3 and will not be. I'm not sure about The Witcher 2, but those other two don't really have open worlds or character AI, do they?
The Witcher 2 isn't even out yet, and the devs plan on releasing it on consoles at some point.
RAGE and Crysis both do. Crysis actually has some pretty advanced AI in engine, and while both kind of take the "checkpoint" approach to open worlds, they're still pretty open. And, if you think about it, with every building in Skyrim having a separate cell instead of them all being rendered in world like in RAGE or Crysis, you could almost say Skyrim is less open world than those two.