Kerr is in phenomenal form but in a rabbited race I'll go with Nuguse. He's consistently beaten him in these sorts of races and he has a faster PR. Jakob would be the favorite with no injuries but it's hard to pick him with so many question marks around his fitness. He's historically been a quick starter though with good performances indoors and early season, so maybe he will prove me wrong and run a world record.
As far as the pacers go, I'll bet they defer to Kerr. Defending world champ, in fine form, just beat Nuguse head to head and also set a world record this year. Gives him a bit of an advantage, but he is a brash runner and might ask for a hot (sub-1:52) pace anyway.