http://members.cox.net/eric2110/V-SYNTH.htm This link has stills taken from the v-synth teaser animation. On the Roland Japan site there is a block diagram of the sound generating circuitry. I think we are looking a 5-octaves and loads of knobs. The block diagram indicates that there are two audio inputs. So it appears to me that the 88-key Fantom mentioned by GK is a different product.
But what is in a name? Roland has V-drums, which I believe are modelled. If the V is "virtual", the new synth may use modeling instead of or in addition to sample-based playback. The analog inputs might support vocoding. I guess this is a successor to the Roland virtual analog synths, rather than a successor to the XV-88, which seem to be what GK is describing. We will know for sure in a week. I am still hoping for that new Roland arranger.