Don't forget that strength-to-weight is a big determinant of acceleration, so the new Roadster wouldn't necessarily need to be AWD. (and here's hoping it's not!)
There are plenty of Benzes, BMWs, and domestic sports/sporty cars with massive acceleration "despite" being RWD. (See all the Viper vs Model S videos, for example)
A Model S drivetrain in something that isn't 2200kg long-wheelbase sedan would be amazing :)
[1] http://techcrunch.com/2015/07/17/surprise-tesla-is-working-o...