de-tuning edges is commonly misconstrued (as is evident from the above messages). To de-tune your edges, you should use a Gummi Stone, or something similar, so as to not damage the edge, but simply make it less sharp. Also, when people get cut by their edges, it is not usually because their edges are sharp, but mostly, because their edges are burred. Removing the burr's will greatly reduce the chance of getting cut by you edges.
De-tuning tips and tails has been done for a while. People would do it all the time with conventional (straight) skis, becuase they were not able to properly engage the tip edge into the new turn. Most of the time, shaped skis do not need, nor should they be de-tuned. The way a shaped ski works is by tipping the ski, causing it to bend, which engages the edges on the tips nad tails. You de-tune, you will not grip properly. Furthermore, de-tuning is not damaging your edges, if you take a file at a 45, or a stone of some variety (be it flat, sharpening, or natural stone) chances are you will damage the edge. A couple extra passes over the tip and tail will do suffice if you choose to de-tune.
What scared me the most about the previous thread is the idea of de-tuning your outside edge. First off, never de-tune a complete edge, that is just plain dumb. You ski with both edges and if you detune one, you are just making things harder on yourself.
Now to say that you de-tune to make initiating the turn easier, well, if if does and you are on shaped skis, you are using ineffective, and inappropriate movements, most likely vertical movements in order to transision from edge to edge. So long as your movements (core movements - waist, hips, shoulders...) are forward/lateral movements, you will not have any problems transitioning from turn to turn.
Oh, BTW, the idea of not de-tuning causing hook-ups, in my opinion and many other top skier I know, this is a myth. It is an excuse for improper movements. Even with conventional skis that were not de-tuned, proper movements allowed proper edge engagement, not edge hook-ups.
Just my 2 cents, but feel free to disagree with me.