According to my sources RR V10 engine is a just a smaller version of the V12 BMW are developing for the 7er & Gran Turismo.
Nothing to do with the S85 V10 engine of M5 / M6 ...
S engines are way too specific to be featured in regular cars ... and especially not cars like RR.
PS: have you noticed the words of Mr. Robertson "brand-new engine for this model
series"!!!??? Just like Scott said: expect coupe & cabriolet variants as well. 4dr coupe variant also possible. And perhaps even a 4dr cabriolet.