I've been emailing skywatcher support back and forth to chase down some questions and they let me know that they have a reducer coming out for full frame at F 5.45 - so doing the math backwards it appears to be a .78x reducer or thereabouts. Retail sometime in January around $380.00
I personally can't wait - not because i'm jumping into a full frame camera immediately, but the flexibility of being able to upgrade is nice but for me - picking off better star shapes with an OAG would be nice...
but more importantly - the backspacing - its supposed to be around 88-90mm backspacing. Means we can finally fit camera rotators on these scopes.