While I believe everyone's honest about the rumors and speculation they've heard, a "Concept V" doesn't seem like the best use of the platform. It won't be a true V90, as that's too far off from production, and we've already heard from the powers that be that none of the 3 concepts will be literal production cars--they are just styling exercises to introduce coming production elements.
So that would leave any V concept likely to be smaller than a production V90, and what more could we learn from that than we did from the Concept XC?
The more visually intriguing use of the platform, IMO, would be a Concept S: We would get to see another form factor. And, it could go either larger than the S80--to please the "boss" and get consumer/journalist/industry feedback--or smaller to test reaction of a future compact.
Of course they could go completely off the deep end and do a motorcycle concept with the Drive-E T6, a grill and t-shaped LEDs, City Safety/Intellisafe 5000+, a comfy seat, and no bodywork at all. It'd be like Volvos version of the Dodge motorcycle with the Viper V10 engine a few years ago.