'Joyn' is the brand name for the RCS services that have been around in the name for a long while. Yesterday someone sent this link for the Fierce Wireless article that had the link to the above Vodafone video.
In theory this sounds great but in practice it may be a bit difficult for operators to sell. One of the selling point for this service is that it is going to be part of the standards so independent of the platform. Android and iOS are the two most popular platforms and more and more users are adopting them. The OTT apps are now available on both these platforms, meaning that it will have mass market adoption. If some other platforms have to succeed then they have to make these most popular apps available on their platform or they will not survive. Microsoft has been rumoured to have paid Rovio to develop the first Angry Birds for the WP platform and they may have to do the same again since the new Angry Birds space is not available on the Windows mobile platform.
In any case, Joyn may be good and it can provide enhanced services but I have a feeling that it may be a bit too little and too late to succeed.