So here is the deal after some research. The Polaris seat upgrades will happen on a rolling basis just like the old businessFirst seats. As of 12/1/16 only new 777-300ER aircraft will have the actual seat and the rest will be re-fit (I presume in HKG as they were last time) and re-inserted into service over the next couple of years.
The soft product was rolled out on a blanked basis as of 12/1/16. So your next flight will at least have the new food, sheets, pajamas, etc.
You'll have to follow the nerds on FlyerTalk (or whatever) for updates on actual aircraft by number as they go out of service and return to service. Obviously, the new seats will be inserted into service on a basis of margin generation (and obviously visibility in the early stages -- routes like ORD-LHR or EWR-HKG.
My guess is the first flight out of Houston with the Polaris seats will be one operated by a competitor (either IAH-LHR, IAH-FRA, or IAH-NRT). Will be a long time before we see it on IAH-MUC, IAH-AMS (small flight), IAH-EZE, IAH-GIG, IAH-SCL, or IAH-LOS (if they ever reinstate that flight)