I think Rudisha looked a lot more impressive in Doha (running 1:43.00) than Kaki did in Hengelo in 1:45.66, with a 27.0 last 200m.
I think the talk of a WR is way off, though Coe's 31 year old stadium record (on a very old track, which has been changed at least twice since then) could go if both/either follow a 50 sec first lap and it doesn't turn into a tactical cat and mouse affair.
I'm going to go for 1:42.25, Rudisha. 1:43.10 Kaki- if he finishes!