Having just read Scott Allen's article on another site about Wallabies bolters, I thought I might partake in this exercise, even though we are still a year and a half out from the RWC.
For the 30/31 man Wallabies squad, the players I would consider 'optimal' would include:
Forwards: Slipper, Kepu, Robinson, Moore, TPN, Horwill, Simmons, Higginbotham, Pocock, Hooper, Palu.
Backs: Genia, Cooper, Leali'ifano, AAC (Adam Ashley-Cooper), Folau.
For the props, it will be interesting to see how Wallabies Ben Alexander and Scott Sio go, and how promising players like Lahiff, Toby Smith, Salesi Manu, Paul Alo-Emile, Ruan Smith etc. fare in Super Rugby this year.
Fainga'a and Hanson at the Reds will surely go head to head with TPN for the back-up.
Douglas is likely to feature in the RWC squad with his experience, and as the only obvious back-up TH lock, but I wouldn't be surprised if Luke Jones, Hugh Pyle, and Cadeyrn Neville push for Wallabies selection.
I left out Fardy, but still expect him, Dennis, and possibly Schatz to feature in the backrow.
Will generally plays 80 minutes, so the bench option is really a toss up between Nic White and Luke Burgess.
Similarly with Quade, though as both Foley and To'omua played well in Super Rugby in 2013, I guess it comes down to form in deciding who is the back-up flyhalf.
Leali'ifano is a certainty with his boot, but it will be interesting to see who Link and co. go with at 12, if they pick a specialist inside centre and not just Lilo and To'omua. Tapuai, Godwin, and Horne (if he's not in Link's bad books).
The outside centre position is likely to be filled by AAC (Adam Ashley-Cooper), with Kuridrani a close second, but could we see Link choosing FTA, or, hell, even CFS or Inman?
And the outside backs; there's far too many to even think of picking the wings so far out from the World Cup.
TL;DR
Bairdy's 23 man Wallabies squad:
Slipper, Moore, Kepu, Horwill, Simmons/Pyle (if Rob is injured), Higginbotham/Fardy, Pocock, Palu, Genia, Cooper, Tomane, To'omua/Godwin, Kuridrani, AAC (Adam Ashley-Cooper), Folau
TPN, Robinson, Manu (yes you read right), Jones, Dennis, White, Tapuai, Beale