You shouldn't need any more. For most people 5x or 6x color wheels are plenty to avoid RBE being an issue, LED machines run 8x that. The DMDs are plenty fast enough for about anything.
What maybe happened (assuming your info is correct), is that they stopped development of a colorwheel based 120Hz system. I'm guessing, based on the lack of faster wheels, that it's impractically difficult to sync a mechanical wheel faster than about 6x, and at that speed, with the sync and every thing, the system has a hard time hitting 8bits/color at just 60Hz. Thus it would be very difficult to maintain the color wheel speed sufficient to mitigate RBE, maintain color depth and keep everything in sync at 120Hz frame rate.
Maybe they saw LED illumination coming and decided it wasn't worth pursuing a low-cost colorwheel based 3D solution when 3-chip is acceptable for the corporate market and LED will be available for the home one?
Or maybe I'm way off base and CM will come in and give me a V8 smack