The drivetrain of TCH is more or less proven. Even though TCH is a year one vehicle, the drivetrain is from Prius. The electronics in TCH are also present in many other Toyota vehicles and I don't see them as source for troubles either. The main issue, if it can be called that, with TCH is the typical year one fit-and-finish issues. Some people find bad fits and rattles. I don't have any issues with mine.

One thing that does concern me is whether hybrid technology will advance significantly in next 3 to 4 years, leaving the Hybrid Synergy Drive system of Toyota dated. I think only that can significantly impact the resale value negatively. Having said that, I don't think that'll happen too soon. Toyota and Honda are basically only two companies that have invested significantly on hybrid technology. Nissan is licensing Toyota, and Ford and GM have a half-assed system. I think given the investment, the product life will be substantially longer than just 3-4 years.

The next breakthrough is more than likely in the battery area, and I don't think retrofitting a next generation battery in TCH will be a difficult proposition, and by then, the battery in TCH may have neared or passed its natural lifespan anyway.

Also, don't forget we have some incidental benefits. I expect the brake wear to be less due to regenerative braking. Interestingly enough, I found more brakepad dust on the rear wheels than front. Well driven TCH could very well stress the internal combustion engine less because of steady RPM. You don't have starter to fail either.