Ideas evolve over time, and the originate from something. Perhaps if inventors were willing to register their invention documents through a set of steps mapping to something like the Technology Readiness Level (http://en.wikipedia.org/wiki/Technology_readiness_level), then they could be eligible for immunity against patent based litigation.
But lets say this certified patent wants to protect its IP on the market through litigation. In this case, the inventor could first request certification of the invention in question before any further legal action occurred.
If we could create a certification process that is less than $2000 or so (about the cost of a provisional patent including attorney fees), it seems feasible. This system would seek to encourage a regulated invention process that filters new inventions from even being eligible for litigation. This allows for inventor insurance in a sense - keeping a capped cost for protecting certifiably original ideas while encouraging original invention and discouraging the incentive behind patent lawsuits.