I think we all agree GPS is a useful tool, but the danger is in becoming too reliant on it.
I think VeeAny is spot on when he makes the distinction between "positional awareness" and "situational awareness".
Its easy to get lulled into a false sense of security when you know exactly where you are on the map, although you may not know where the nearest wires/big tree/hill etc is. To retain control, you also need a good attitude reference, especially in a helicopter without full stabilisation (attitude hold). Its very easy to lose the horizon in deteriorating weather, even though you may know where you are, and can see the ground below. Disorientation can come very rapidly thereafter, especially if you start to manoeuvre, either to find a landing spot or to turn around.
I agree 100% with JTobias - I think there needs to be much better training in terms of recognizing the onset of weather limitations, and what to do when it happens. If you read CAP 780 aviation safety review 2008, or CAA paper 2007/03 "helicopter flight in degraded visual conditions", it quickly becomes apparent that press-onitis/inadvertent imc/disorientation is a factor in a huge chunk of the accident database for small helicopters.