Well, Sculthorpe's injury makes things interesting
Ok, time to bite the bullet and weigh in with my predictions:
1. Wellens
2. Carney
3. Senior
4. Gleeson
5. Calderwood
6. Cooke (a bolter I know!)
7. Long (vc?)
8. Fielden
9. Cunningham
10. Morely
11. Ellis
12. Peacock (c)
13. Sinfield
14. Diskin
15. Bailey
16. Thackray
17. Johnson
18. Maguire
19. Burrow
20. Reardon
21. Diskin
22. Fozzard
23. King
24. Langley
25. Walker
Injured: Sculthorpe, Radlinksi, O'Loughlin...
I think with the absence of experienced leaders, they will stick with some experienced GB-heads like Cunnigham and Long. With Sinfield's ability to shift into the halves, I think they would be well advised to go in with 3 forwards on the bench to match the Aussies, and one spark player in Diskin (to releive Cunningham, who can than come back eslewhere in the forwards).
Bench and fringe player roles will be hotly contested, and could really go anywhere. I'd expect some of those players 18-25 to get a look in across the four/five games, depending on injuries and results.