One of the big things they can do to make it a hit is the design and execution of the cabin. The Cirrus G6 instrument panel is a good example of what is possible. It looks pretty cool, and it's laid out to be functional as well. Mooney should hire a design firm to explore the possibilities. For over half a century the cabin design of small aircraft has been static. Wake it up.
Regarding performance possibilities, I think composite construction should make building a pressurized aircraft much simpler. The manufacturer should be able to build a cabin that has very few paths for air to escape, which means it will require less energy to produce a pressurized environment. Every pressurized piston engined aircraft in production uses a turbocharger to provide cabin pressure. We know that turbocharging places a performance penalty on engines, and they can also affect engine longevity. If an aircraft cabin is built to absolutely minimize leakage, would it be possible to use an electrically driven fan to provide pressurization? A fuselage with leakage equivalent to a two square inch opening should be possible. The fan wouldn't need to produce a lot of volume, just a high static pressure differential. A 1/2 HP fan might do it, in a 28 VDC system that would draw 40 amps. Counting system losses, an alternator producing that amperage would require about 1.7 HP.
But then again it's probably a bad idea for several reasons.