I've seen some people on other forums say they prefer smilies to be denoted in such a way that could not be typed accidentally, and don't like it when boards replace text smilies with images. For example,
should be displayed as a colon followed by a capital D, and the image

should be denoted by something like :grin:.
I personally agree with that, but then there's the question of how to implement that without mutilating existing posts. I mean, we could theoretically run a script to replace all instances of the colon-D (outside of code tags and such) with :grin:, and so on. Or something like that.
And then there might be some who would oppose such a change.