I think at the start of the year Tremlett would have gotten a go, but he's been pretty average for the last couple of months and I wouldn't risk him in such a big game. The other bowling option is Jon Lewis, but I cannot see them picking him ahead of Tremlett, as it is more of a Tremlett pitch and hes been ahead in the pecking order since the 1st test.
Collingwood has been in good form with the bat and would probably be fighting it out with Joyce if a batsmen is preferred - a distinct possibility as we only need to draw the Test. I also think someone like Collingwood bowling negative away swingers outside off isnt a bad tactic. When Bell bowled against Clarke i thought he was a bit unlucky not to get a wicket, they just can't help themselves and often have needless slashes outside off.