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.