Sorry Michi, just noticed your post up there. Not really, I kept the rule after that year because I realized that at any time there could be hazards on the floor that we don't see, whether it might be broken glass from a dropped cup or cords running across a hall or anything else that could happen. I expect the new guys probably keep it for the same sort of general safety reason. The razor blades were a direct result of hotel irresponsibility, so I'll just say that there is more than one reason we *left* that hotel, but the current hotel is much more sane - I wouldn't expect any such nonsense with them. It's not likely we'll experience crazy hotels attacking our feet again, but it is wise to plan to be safe whatever accident might happen, so shoes are always good. 
I really don't get your need for a long-winded reply. It confuzzled my head.. as it seemed like you were arguing against something nonexistant. o_O; I was making a comparsion to Halloween Candy..
Child- I'm going trick or treating!
Mother: Be careful! They put razor blades in the apples!
Now, we all know that the chances of finding a blade in your candy is nigh nonexistant, it's still a good thing to say, it enforces checking your candy and being safe ^_^
NDK goer- I can't wait for NDK!
NDK goer 2- Make sure not to go barefoot! Did you hear about the razor blades?
Will razor blades scattered about happen again? Maybe not.. but if someone asks why they should wear shoes.. it's a good -example- to use. Along with wires, broken glass, pins and pointies falling off costumes, getting your piggies stepped on.....
I didn't mean it in the sense that razor blades on the carpet -would- happen again. I meant it in the sense of, will it become something that more experienced con goers talk about to newer ones?
On the other note, as far as what Detonate Infinity said about some costumes being offensive, and the arguement that NDK has rules to ban offensive costumes..
Well, I know people who think that a mini-skirt or showing any type of cleavage is offensive. The "I love Yaoi!" t-shirts could also be considered offensive to some. In other words, while NDK can narrow it down to block the most extremes, ANYTHING can be offensive, can't it? :p