According to Autocar, the new Mini Roadster will be a near-production-ready concept car, similar to the Mini Traveller concept that was a near-production version of the Crossman crossover vehicle.
The Roadster will be strictly a two-seater and will offer a sportier look than the current Mini Convertible. It will be based on the current-generation Mini, but with a lower roofline and windshield.
So far the engine lineup has not been confirmed, but a lineup similar to those offered in both the coupe and convertible Mini Coopers is expected. This includes the potent John Cooper Works engine.
The Mini Roadster will reportedly go on sale in 2010 after the upcoming Mini Crossman. It is expected that Mini will develop a sixth model sometime in the near future.
Source: Autocar