I think the GPS discussion is an interesting one. I've been saying for a while now that i think some form of GPS might become mandatory in the future. Not as a form of primary navigation, but as an aid for situation awareness with airspace and as a quick reference in the event of getting lost.
I fly with a Garmin 430 and a 530 and i use them for navigation, but not my primary form of nav. I feel very uncomfortable without a written plog and a chart on my lap. My opinion is that if its there, you might as well put it to use.
I agree that IFR nav is ALMOST impossible without a GPS, but i think its extremely important to know how to fly IMC without one. Electrics can fail.
I also wonder how long it will be until GPS training is a part of the PPL syllabus?