Fairchild XC-120 Packplane
Sikorsky Skycrane with Mission Pod
The one case in which a passenger pod might make some sense would be on helicopters used for offshore work. In the event of ditching, by having passengers are already contained within something similar to a freefall lifeboat, they would not have to try and leave an inverted, submerged cabin and then try to inflate and board a life raft.