Well, there was this rumor of the soon-to-be-released
Monoray line of in-wall / on-wall ESL.
But my take is that the Masterpiece line is pretty solid and will be around for another couple of years. Maybe a tweak here and there.
One thing I'd love to see is the option to active crossover these units.
Another option I'd like to see is an integrated system approach with an ML-certified processor configuration using the powerful Trinnov Altitude line. This would be a complete system with a processor, amplifiers, and active speakers. Able to integrate multiple subwoofers, and leveraging the highly effective Trinov room correction, a system deployed into a well-designed and treated listening room / theater would deliver massive results.
The ability of a Trinnov to provide not only the preamp functions but to also perform all the duties of a speaker processor, with crossovers, delay management, and speaker EQ, along with the system-wide room correction, all in a single unified platform is transformative.
The value to a customer to be able to purchase a certified ML-designed system that is guaranteed to get the most out of the speakers and the room they are placed in is huge.
As someone who has rolled their own version of the above, I assure you that the hundreds of hours of XO tuning, amplifier matching, and overall system tuning are something that takes skill as well as time.