Out of the current Queensland side, I reckon the following will still be playing first grade...
Darius Boyd - 29
Cooper Cronk - 33
Matt Gillett - 28
Ben Hannant - 32
Greg Inglis - 30
Nate Myles - 32
Dane Nielsen - 32
Matthew Scott - 31
Cam Smith - 34
Dave Taylor - 28
Ben Te'o - 30
Sam Thaiday - 32
Jonathan Thurston - 34
Jharal Yow Yeh - 28
Whether those 32+ year olds will be Origin standard remains to be seen but I can see a few of them sticking around.
Coming through the ranks...
Corey Norman - 26
Andrew McCullough - 27
Josh McGuire - 27
Dale Copley - 26
Kurt Baptiste - 26
David Hala - 28
Lachlan Maranta - 25
Aaron Whitchurch - 25
Mitchell Frei - 25
Edrick Lee - 25
Ben Barba - 28
Matt Srama - 26
Daly Cherry-Evans - 28
Dane Gagai - 26
Ray Thompson - 27
James Segeyaro - 27
Michael Morgan - 26
Patrick O'Hanlon - 26
Junior Vaivai - 27
Daniel Vidot - 27
Jake Friend - 27
Lama Tasi - 27
Aidan Guerra - 29
Martin Kennedy - 28
Tautau Moga - 24
Then you have 20s players like Caleb Timu, Francis Molo, Corey Oates, Soape Palau, Anthony Milford, Malcom Congoo, Moses Mybe, Hymel Hunt, Sam Harrold, Ben Hampton, Kurt Mann, Korbin Sims, Zac Santo, Chris Grevmuhl, Luke Keary, Dylan Napa, Tuiala Togitasi etc. etc. who could become anything.
With the potential of Folau & possibly Hunt returning we should be alright. I don't think we'll see any selections like Flannery @ five eigth.