I'm all for variety, but you know some subclasses would still be able to slide as their unique ability, and their slides would have to be buffed to be much more dynamic than they are now in order to compete with moves like Shadestep. [i]I'd[/i] probably be okay with it, but I'm not sure [i]you'd[/i] like how that'd turn out.
Not every idea comes out perfectly in the first run, so yeah some stuff would have to be tweaked to make it viable and not over-powered. I know the general rule has been "If it's all broken, then it's fixed", but that can't be said for all aspects. I just know many people who would kill to take out the slide itself. If they made it something more unique, we could get something that can't be related to CoD at all.