Interesting video, but a few comments:
One poster mentioned about a large number of O-rings - I don't see so. The plunger looks like a finely machined control valve, like what an automatic tranmission uses to for the gear selection. You move the car into drive, and that moves a control valve that looks similar to this, which puts oil pressure into certain passages. This control valve system has proven very reliable for decades already.
The main mod of failure that I can see is the solenoid which controls the control valve burning out, which shouldn't be a horribly expensive or difficult fix.