The nice thing too see is that the Wallabies don't need to rebuild the team from scratch moving forward. In fact in nearly every position we have a strong foundation of established players that should remain in the picture up to 2019.
Back-row
The back-row has really been the corner stone of the Wallabies this season and I think we'll see that continue over the next 4 years. Pocock and Hooper will presumably both be there in 2019, barring some major injury to Pocock (if anything the 2 seasons he missed should prolong his career).
As a result I think we'll see Chieka develop the team around the 2 open-side approach. We have the depth to do it consistently with the likes of Gill (similar to Pocock) and McMahon (similar to Hooper) available. No reason we can't employ that in most test matches.
Importantly, we'll need to find the right 4/5/6 combination to compliment the 2 openside game plan. Most immediately, will be finding Fardy's long term successor. I think Luke Jones is the most obvious candidate, although he needs to develop his line-out skills over the next few years. Lopeti Timani is in the same boat.
Lock
In terms of second row I suspect Simo/Douglas/Carter will be the constants, and Cheika will need to develop a few more younger options - and as others have mentioned there's plenty of good options coming through the ranks (Adam Coleman and Rory Arnold appear to be the next cabs off the rank). I suspect this could actually become an area of strength for us. Skelton certainly has the potential to be an important part of the wallaby set up but really needs to develop his set piece skills.
Scrum
I'm really hoping they keep Mario Ledesma around for a while to continue his good work. I'd like to see Cheika bring in a handful of new front rowers next year to ensure that our FR stocks are deep come 2019. Sio/Slipper/Smith/Hanson is a really strong base to work from. Who's next in line will be interesting. Tolu Latu is most likely to become a mainstay IMO. after him I'm not sure who the best options are. Cheika has shown he's happy to look abroad for talent and I'd wager he'll probably lure PAE home before 2019, but in the meantime I'm happy with him developing his set piece in the northern hemisphere.
Backs
The majority of our backline should remain very stable over the next four years. The guys that really stand out for me as most likely to join the team are Stirzacker, Debracini, Kerevi and Taqele.
New Zealand
Looking forward I'm really confident that we can turn around our results against NZ over the next few years and win back the bledisloe. We are much better placed than they are at least over the next few years. Yes New Zealand has a production line of brilliant talent and depth is not a problem for them but you have to look at the personnel they are replacing. McCaw is essentially irreplaceable, not just become of his experience but for his leadership. Sam Cane is a talented guy but he'll never reach Ritchie's heights. Kaino is heading off into the sunset and the other mainstays in their backrow (Reid/Messam) are all unlikely to be with the team in 2019. Considering the strength of our backrow that has to be a concern. Just as concerning will be the loss of the Nonu/Smith combo which has been a rock for the team over the last 4 years. The All Blacks will need to build a backline around Aaron Cruden but that could take time.