ALMS Top tier to go diesel?

Speculation has it that with Audi’s Le Mans-dominant R-8 now headed for retirement, the company’s replacement will be an R-10 Diesel because more than 50% of Audi's sales are diesel! And some speculate that with Porsche entering the LMP2 class next year that they too are reportedly considering a Diesel competitor for LMP1 to go up against Audi. However, somehow we don't see a diesel engine in a Porsche as a good fit.