If you go back after escaping Wheatley's first trap, he tries very hard to convince you to jump into the pit. Sounds like there's some great stuff down there.
Also, here's two videos showing Portal 2 in third-person (fyi, there's a childish, leering moment late in the second video, but it's otherwise very cool):
And while I'm at it, here's the every end of Portal 1 in third person:
*Buy Companion Cubes at eBay.