From what I gather Naim hoped to have it ready in January, but they found a number of challenges getting the older streaming engine updated to enable use of the new in-house radio service, I guess because of limited onboard resources - it was never originally envisaged as being required all those years ago when it was originally developed. However, they do hope to have it ready ASAP. We may well hear more when Naim updates us all on the Vtuner situation on Monday.
Until then, there are some other ways you can route IR to your Superuniti - see the sticky thread for details.