Reading a little into the lineup, I'd speculate that the following positions are up for grabs next weekend against Wales:
Lock: I'd say that no Simmons in this team means he'll be starting next week. Horwill, Carter and Skelton are playing off for the other starting role and a bench spot.
Haflback: Genia and White are playing off to be Nick Phipps' backup. Genia starting would indicate to me he's more likely.
Inside centre: To'omua and Leali'ifano are playing off for this one. Despite Lilo's excellent test against the All Blacks, To'omua starting seems to indicate he's being counted as the incumbent.
Outside centre/Wing: AAC (Adam Ashley-Cooper) will come back into this side next week. I'm guessing he'll just take Horne's wing spot and Horne and Tomane are playing for a bench spot unless Speight struggles for some reason.
I think Hodgson and McMahon could be playing off for a bench spot next week unless Cheika has thoughts of giving Hodgson a crack at 6.