Single? Don't think so.
I heard the new addition to the HP range, the HP1, may use the Aprilia 450 vee-twin power plant.
There are some stompping 4 stroke >500cc engines now and I'm looking forward to seeing the HP1, but I hope the present 650 single donkey is not the answer to BMW's which engine shall we use question!
Believe me, if they get the engine choice right for the market's need (ie.not just make a 'bling' bike for flash 4ker's to blat around our city's streets),I'll be the first to buy a light Jap or KTM threatening machine able to handle some challenging off road grief.
Ten years ago, Honda bowled us over with the XR400R so it would be nice for the Germans to produce a lighter, more powerful bike, with such a power curve that the pilot doesn't need to be a top moto-x rider.
I'll hang on to my Y2K DRZ400 for the time being, which replaced my '97 XR4 that was abused all over Europe without a glitch. The money is burning a hole in my palm though. T.