Now, you get to choose between HK and... HK. 9" or 11". All in black.
As for the future, Geisselle had a rail that seems most likely to get released to the public, but haven't seen any updates with a firm timeline. Remington Defense displayed a similiar rail, but doubtful they'll release it to civilians. Daniel Defense had an MFR style tube rail for display, but again, no firm release date. All these options were slick forends with bolt on rail sections.
IMO Geisselle looked the most promising and it was designed for a government contract. Curious how it will handle heat, though, as my experience with the Daniel Defense tube rail was that they get a lot hotter a lot faster.