I appreciate Mottram as although he's running under the Australian flag I feel he is partly ours (two British parents and lives most of the year in britain and last I heard a British girlfriend). He's someone whos not only good enough to compete with the Kenyans and Ethiopians but potentially beat them as well.
That said over 5k at the moment in the world I would rank him in the top 5 but probably no higher. Choge, Songok, Bekele (K) and Lagat I would all imagine could take him. Whether they all compete (a few out of Choge, Songok and Lagat will compete over 1500 and I think Bekele has already said he's just competing over 10000?) is doubtful and I think he will go into that final with a definite medal shot.
His real trashtalking only seems to have occured recently though, as far as I'm aware he hasn't been this "bad" until he really started beating the top athletes in the world. In my mind once you've beaten Kenenisa in a race then you've got bragging rights. After seeing him race so strongly against Geb in London, he's arguably one of the best finishers in the world.
Agree with comments re: Tariku, I don't think anyone gives him enough credit for his own performances as he is definitely developing into a world class performer, okay he's getting beaten by Mottram but he's also improving fast. Has definitely helped this season not pacing as much for big brother.