Given the original deal to provide Now TV on BT TV was first announced in December 2017, many have given up holding their breath on Now TV's inclusion. Previously announced timeframes have come and gone. However in recent months, some activity including end-user testing has been spotted in preparation for a full roll-out.
Now TV on BT TV would enable BT TV customers to access all of Sky's entertainment and sports channels via the one receiver, including the recently launched Sky Crime and Sky Comedy channels.
On the flipside of the coin, Sky customers are now able to call Sky to add BT Sport to their Sky TV package, rather than having to add BT Sport separately via BT. It's not yet known when this service will be made available online.
FYI that I do not work for NOW, just a NOW customer trying to help