Fear not, you can have PT-6's put on your Duke now.
http://www.royalturbine.com/
They'll also put them on a Baron. MGTOW single engine rate of climb is like 1700 FPM
http://www.cougarbaron.com/
There are other options coming along as well. Several 100LL drop in replacements are showing promise, most notebly Swift Fuel. Diesel is also showing promise. Cessna is cancelling production of the Turbo 182 in place of a Diesel 182. TCM is also working on an STC for a diesel conversion for the Bonanza and Baron. And there are others....
Not all hope is lost for GA.
yeah because we all make enough money to buy this stuff.