There is a thread ongoing in Rumours and News about an airplane that was vectored by LAX ATC the wrong way, putting them towards Mount Wilson. If this was to ever happen in say a Norwegian Fjord, that would be another example of what could go wrong.
Obviously a heavy aircraft will not be able to out-manoeuvre a smaller GA aircraft, so the escape manoeuvres will need to be different. If the GPWS is triggered it will always offer the instruction.. 'Pull Up, Pull Up.', but that assumes that you have some excess energy available.