Well, the two examples in my post not withstanding, let's say the platforming sections preceding the helicopter fight in Tibet.
You climb up on a beam and expect to climb across it because that's what the game has conditioned you to do (just prior to this you climb up a hotel, which in itself had a few moments of things not going as you'd expect and even required a, gasp, DIAGONAL jump, which is a bit risque in UC's platforming space), only to have your expectations fucked with as a helicopter (which has been foreshadowed earlier on in that oh so fashionable way) shoots your pathway into oblivion and knocks the structure your climbing back in on itself.
You're then forced to jump over a few platforms, climb up a sign which gets knocked over in the cross-fire and jump into an arena of guys shooting at you and seamlessly proceed to have a cover-based fight with the helicopter blowing pot-plants and grenades every which way.
This is the game at its best, when its playing with everything you've been conditioned to expect and makes you use all your skills together in a way you'd not have expected, but at the same time never makes you step outside yourself at the time and think "oh, here's this section, now this section". You don't think about it until you look back on it, and i think that's UC2's greatest success.