ANAKIN: Hello, my name is Darth Va...no, you see? I'm hopeless! It's all over! I might as well go kill myself now to save you all the trouble... *sobs miserably* I killed *crazed look* Younglings!
Obi-Wan didn't want to save him, but he didn't want to murder him. He let Anakin do it himself. Hell, most of Anakin's de-limb-ment was his own doing, the way he was jumping.
I would have to say that Obi-Wan would take Anakin's lightsaber and arrest him, yeah.
I think it's a bunch of bullshit when they he has the higher ground he would definitely win. Remember TPM when Darth Maul was standing above him and he was in the pit. right when Obi jumped up he could have cut him down because he did not have a saber in his hand at all. But since anakin is such a jackass he got chopped. Well if Anakin did not jump directly at Obi and more to the side he would have had an equal chance. and the fight would have went on
I think Obi was speaking both literally and figuratively when he said this line.. not only was Obi literally on higher ground than Ani, they had trained & fought together for 15 years.. Obi taught Ani and knew what his fighting strategy AND his weaknesses were (Nic G has said from the jump that Ani is vulnerable on a slope, which is where Obi was standing).. he knew that if Anakin did try the jump he could and would have to take him out but was trying to warn Anakin to back down ny saying this line IMO
To me it was Obi-Wan outsmarting Anakin by preying on his overconfidence. It's like Obi-Wan said, "Hahahaha... I can do it but you can't..." because he knew Anakin would try it anyway. He even says that... "Don't try it!" because he knows Anakin will disobey him and he wants Anakin to jump.
Anakin takes the bait... jumps like a bafoon and gets completely disfigured!