Most of you know this, OEM's are working on multiple engine projects constantly, most never get out of Engineering. 4S's, turbos, chargers, DI, etc.
Bottom line - Poo has to improve their emission standings, which means a combo of more 4S's, DI, especially if HP goes up. Emission limits are impacted by HP ratings, also (read no more M1000, cat scrapped the 600, don't think that wasn't a driver). My rules of thumb:
First DI will be in a 6, before an 8. No 8 DI in 13. I think they are still gunshy of any bold new big bore motors after the laydown 860, then CFI4 800 debacles. They should be, too. They were idiots. Some of those idiots still sulk in the halls of Poo.
Could be a 4S turbo offering, Poo and Doo are watching cat closely. Poo has a great 600, less HP means less emission impact. Don't think Poo will dump the 600 for a 4S alla cat, cat's 600 was third string, but, it's a tooling and production cost thing, too. Poo will want to stop getting pummeled on the HP playground, especially in the flats, where there still sell some sleds.
An 800ho is a possibility for 13, but not without some offsetting emission strategy via 4S or DI. Something that leverages past engineering. SWAG's.